30939640 has 16 divisors (see below), whose sum is σ = 69614280. Its totient is φ = 12375840.

The previous prime is 30939631. The next prime is 30939647. The reversal of 30939640 is 4693903.

It is a super-2 number, since 2×30939640² = 1914522646659200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 30939596 and 30939605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30939647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 386706 + ... + 386785.

Almost surely, 2^30939640 is an apocalyptic number.

It is an amenable number.

30939640 is an abundant number, since it is smaller than the sum of its proper divisors (38674640).

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

30939640 is a wasteful number, since it uses less digits than its factorization.

30939640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773502 (or 773498 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 34.

The square root of 30939640 is about 5562.3412336893. The cubic root of 30939640 is about 313.9340470296.

The spelling of 30939640 in words is "thirty million, nine hundred thirty-nine thousand, six hundred forty".