20925864 has 80 divisors (see below), whose sum is σ = 60054720. Its totient is φ = 6804000.

The previous prime is 20925847. The next prime is 20925881. The reversal of 20925864 is 46852902.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20925847) and next prime (20925881).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 27489 + ... + 28239.

It is an arithmetic number, because the mean of its divisors is an integer number (750684).

Almost surely, 2^20925864 is an apocalyptic number.

20925864 is a gapful number since it is divisible by the number (24) 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 20925864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30027360).

20925864 is an abundant number, since it is smaller than the sum of its proper divisors (39128856).

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

20925864 is a wasteful number, since it uses less digits than its factorization.

20925864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 812 (or 799 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 20925864 is about 4574.4796425386. The cubic root of 20925864 is about 275.5673751530.

The spelling of 20925864 in words is "twenty million, nine hundred twenty-five thousand, eight hundred sixty-four".