20208864 has 48 divisors (see below), whose sum is σ = 57132432. Its totient is φ = 6217728.

The previous prime is 20208863. The next prime is 20208887. The reversal of 20208864 is 46880202.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20208863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6849 + ... + 9344.

It is an arithmetic number, because the mean of its divisors is an integer number (1190259).

Almost surely, 2^20208864 is an apocalyptic number.

20208864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20208864 is an abundant number, since it is smaller than the sum of its proper divisors (36923568).

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

20208864 is a wasteful number, since it uses less digits than its factorization.

20208864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16219 (or 16211 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 20208864 is about 4495.4270097511. The cubic root of 20208864 is about 272.3833981960.

The spelling of 20208864 in words is "twenty million, two hundred eight thousand, eight hundred sixty-four".