20451864 has 32 divisors (see below), whose sum is σ = 51750720. Its totient is φ = 6734496.

The previous prime is 20451859. The next prime is 20451877. The reversal of 20451864 is 46815402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3142 + ... + 7125.

It is an arithmetic number, because the mean of its divisors is an integer number (1617210).

Almost surely, 2^20451864 is an apocalyptic number.

20451864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20451864 is an abundant number, since it is smaller than the sum of its proper divisors (31298856).

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

20451864 is a wasteful number, since it uses less digits than its factorization.

20451864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10359 (or 10355 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 20451864 is about 4522.3737129963. The cubic root of 20451864 is about 273.4708026856.

The spelling of 20451864 in words is "twenty million, four hundred fifty-one thousand, eight hundred sixty-four".