20858731065 has 32 divisors (see below), whose sum is σ = 37162391040. Its totient is φ = 11100595968.

The previous prime is 20858731057. The next prime is 20858731087. The reversal of 20858731065 is 56013785802.

20858731065 is a `hidden beast` number, since 2 + 0 + 8 + 587 + 3 + 1 + 0 + 65 = 666.

It is not a de Polignac number, because 20858731065 - 2³ = 20858731057 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 20858731065.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 104352 + ... + 229361.

It is an arithmetic number, because the mean of its divisors is an integer number (1161324720).

Almost surely, 2^20858731065 is an apocalyptic number.

It is an amenable number.

20858731065 is a deficient number, since it is larger than the sum of its proper divisors (16303659975).

20858731065 is a wasteful number, since it uses less digits than its factorization.

20858731065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334190 (or 334184 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 20858731065 in words is "twenty billion, eight hundred fifty-eight million, seven hundred thirty-one thousand, sixty-five".