30920820 has 96 divisors (see below), whose sum is σ = 100251648. Its totient is φ = 6974592.

The previous prime is 30920803. The next prime is 30920831. The reversal of 30920820 is 2802903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34417 + ... + 35303.

It is an arithmetic number, because the mean of its divisors is an integer number (1044288).

Almost surely, 2^30920820 is an apocalyptic number.

30920820 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30920820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50125824).

30920820 is an abundant number, since it is smaller than the sum of its proper divisors (69330828).

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

30920820 is a wasteful number, since it uses less digits than its factorization.

30920820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 989 (or 987 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 30920820 is about 5560.6492426694. The cubic root of 30920820 is about 313.8703807304.

The spelling of 30920820 in words is "thirty million, nine hundred twenty thousand, eight hundred twenty".