31972440 has 128 divisors (see below), whose sum is σ = 103968000. Its totient is φ = 7838208.

The previous prime is 31972433. The next prime is 31972469. The reversal of 31972440 is 4427913.

It is a happy number.

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 = 31972398 and 31972407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 84171 + ... + 84549.

It is an arithmetic number, because the mean of its divisors is an integer number (812250).

Almost surely, 2^31972440 is an apocalyptic number.

31972440 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 31972440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51984000).

31972440 is an abundant number, since it is smaller than the sum of its proper divisors (71995560).

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

31972440 is a wasteful number, since it uses less digits than its factorization.

31972440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449 (or 445 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 31972440 is about 5654.4177419076. The cubic root of 31972440 is about 317.3890409383.

The spelling of 31972440 in words is "thirty-one million, nine hundred seventy-two thousand, four hundred forty".