30939840 has 112 divisors (see below), whose sum is σ = 109179360. Its totient is φ = 8248320.

The previous prime is 30939817. The next prime is 30939841. The reversal of 30939840 is 4893903.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 30939795 and 30939804.

It is not an unprimeable number, because it can be changed into a prime (30939841) 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, 6850 + ... + 10430.

Almost surely, 2^30939840 is an apocalyptic number.

30939840 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 30939840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54589680).

30939840 is an abundant number, since it is smaller than the sum of its proper divisors (78239520).

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

30939840 is a wasteful number, since it uses less digits than its factorization.

30939840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3607 (or 3591 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 30939840 is about 5562.3592117015. The cubic root of 30939840 is about 313.9347234722.

The spelling of 30939840 in words is "thirty million, nine hundred thirty-nine thousand, eight hundred forty".