20864868 has 12 divisors (see below), whose sum is σ = 48684720. Its totient is φ = 6954952.

The previous prime is 20864863. The next prime is 20864923. The reversal of 20864868 is 86846802.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (20864863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 869358 + ... + 869381.

It is an arithmetic number, because the mean of its divisors is an integer number (4057060).

Almost surely, 2^20864868 is an apocalyptic number.

It is an amenable number.

20864868 is an abundant number, since it is smaller than the sum of its proper divisors (27819852).

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

20864868 is a wasteful number, since it uses less digits than its factorization.

20864868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1738746 (or 1738744 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 42.

The square root of 20864868 is about 4567.8077893011. The cubic root of 20864868 is about 275.2993676511.

The spelling of 20864868 in words is "twenty million, eight hundred sixty-four thousand, eight hundred sixty-eight".