30921420 has 24 divisors (see below), whose sum is σ = 86580144. Its totient is φ = 8245696.

The previous prime is 30921391. The next prime is 30921427. The reversal of 30921420 is 2412903.

It is a super-2 number, since 2×30921420² = 1912268429632800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (30921427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 257619 + ... + 257738.

It is an arithmetic number, because the mean of its divisors is an integer number (3607506).

Almost surely, 2^30921420 is an apocalyptic number.

30921420 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

30921420 is an abundant number, since it is smaller than the sum of its proper divisors (55658724).

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

30921420 is a wasteful number, since it uses less digits than its factorization.

30921420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515369 (or 515367 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 30921420 is about 5560.7031929424. The cubic root of 30921420 is about 313.8724108729.

The spelling of 30921420 in words is "thirty million, nine hundred twenty-one thousand, four hundred twenty".