30973440 has 160 divisors (see below), whose sum is σ = 102627360. Its totient is φ = 7962624.

The previous prime is 30973417. The next prime is 30973447. The reversal of 30973440 is 4437903.

It is a tau number, because it is divible by the number of its divisors (160).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 30973398 and 30973407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30973447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 284106 + ... + 284214.

It is an arithmetic number, because the mean of its divisors is an integer number (641421).

Almost surely, 2^30973440 is an apocalyptic number.

30973440 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30973440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51313680).

30973440 is an abundant number, since it is smaller than the sum of its proper divisors (71653920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

30973440 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (30973439) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (172).

30973440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 156 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 30.

The square root of 30973440 is about 5565.3786933146. The cubic root of 30973440 is about 314.0483244759.

It can be divided in two parts, 30973 and 440, that added together give a palindrome (31413).

The spelling of 30973440 in words is "thirty million, nine hundred seventy-three thousand, four hundred forty".