30921939 has 16 divisors (see below), whose sum is σ = 46259200. Its totient is φ = 20412648.

The previous prime is 30921923. The next prime is 30921941. The reversal of 30921939 is 93912903.

It is not a de Polignac number, because 30921939 - 2⁴ = 30921923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30921239) 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, 2779 + ... + 8340.

It is an arithmetic number, because the mean of its divisors is an integer number (2891200).

Almost surely, 2^30921939 is an apocalyptic number.

30921939 is a deficient number, since it is larger than the sum of its proper divisors (15337261).

30921939 is a wasteful number, since it uses less digits than its factorization.

30921939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11231 (or 11225 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 30921939 is about 5560.7498595064. The cubic root of 30921939 is about 313.8741669250.

The spelling of 30921939 in words is "thirty million, nine hundred twenty-one thousand, nine hundred thirty-nine".