30920868 has 72 divisors (see below), whose sum is σ = 86145696. Its totient is φ = 9273600.

The previous prime is 30920861. The next prime is 30920881. The reversal of 30920868 is 86802903.

It is a super-2 number, since 2×30920868² = 1912200155746848, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (30920861) 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 23 ways as a sum of consecutive naturals, for example, 44403 + ... + 45093.

It is an arithmetic number, because the mean of its divisors is an integer number (1196468).

Almost surely, 2^30920868 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30920868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43072848).

30920868 is an abundant number, since it is smaller than the sum of its proper divisors (55224828).

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

30920868 is a wasteful number, since it uses less digits than its factorization.

30920868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825 (or 820 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 30920868 is about 5560.6535587105. The cubic root of 30920868 is about 313.8705431428.

The spelling of 30920868 in words is "thirty million, nine hundred twenty thousand, eight hundred sixty-eight".