30975021 has 64 divisors (see below), whose sum is σ = 58613760. Its totient is φ = 15698880.

The previous prime is 30975017. The next prime is 30975023. The reversal of 30975021 is 12057903.

It is not a de Polignac number, because 30975021 - 2² = 30975017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30975023) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 97555 + ... + 97871.

It is an arithmetic number, because the mean of its divisors is an integer number (915840).

Almost surely, 2^30975021 is an apocalyptic number.

It is an amenable number.

30975021 is a deficient number, since it is larger than the sum of its proper divisors (27638739).

30975021 is a wasteful number, since it uses less digits than its factorization.

30975021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391 (or 385 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 30975021 is about 5565.5207303540. The cubic root of 30975021 is about 314.0536677846.

It can be divided in two parts, 3097 and 5021, that added together give a palindrome (8118).

The spelling of 30975021 in words is "thirty million, nine hundred seventy-five thousand, twenty-one".