30957921 has 12 divisors (see below), whose sum is σ = 45256848. Its totient is φ = 20389464.

The previous prime is 30957919. The next prime is 30957923. The reversal of 30957921 is 12975903.

It is an interprime number because it is at equal distance from previous prime (30957919) and next prime (30957923).

It is not a de Polignac number, because 30957921 - 2¹ = 30957919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (30957923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19975 + ... + 21468.

It is an arithmetic number, because the mean of its divisors is an integer number (3771404).

Almost surely, 2^30957921 is an apocalyptic number.

It is an amenable number.

30957921 is a deficient number, since it is larger than the sum of its proper divisors (14298927).

30957921 is a wasteful number, since it uses less digits than its factorization.

30957921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41532 (or 41529 counting only the distinct ones).

The product of its (nonzero) digits is 17010, while the sum is 36.

The square root of 30957921 is about 5563.9842738814. The cubic root of 30957921 is about 313.9958652274.

Subtracting from 30957921 its product of nonzero digits (17010), we obtain a triangular number (30940911 = T₇₈₆₆).

It can be divided in two parts, 30957 and 921, that added together give a triangular number (31878 = T₂₅₂).

The spelling of 30957921 in words is "thirty million, nine hundred fifty-seven thousand, nine hundred twenty-one".