20256899 has 4 divisors (see below), whose sum is σ = 21815136. Its totient is φ = 18698664.

The previous prime is 20256889. The next prime is 20256931. The reversal of 20256899 is 99865202.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20256899 - 2²⁰ = 19208323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20256889) 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, 779099 + ... + 779124.

It is an arithmetic number, because the mean of its divisors is an integer number (5453784).

Almost surely, 2^20256899 is an apocalyptic number.

20256899 is a deficient number, since it is larger than the sum of its proper divisors (1558237).

20256899 is a wasteful number, since it uses less digits than its factorization.

20256899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1558236.

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 20256899 is about 4500.7664902770. The cubic root of 20256899 is about 272.5990392744.

The spelling of 20256899 in words is "twenty million, two hundred fifty-six thousand, eight hundred ninety-nine".