20856554415 has 24 divisors (see below), whose sum is σ = 36214717968. Its totient is φ = 11104001280.

The previous prime is 20856554413. The next prime is 20856554437. The reversal of 20856554415 is 51445565802.

20856554415 is a `hidden beast` number, since 2 + 0 + 8 + 56 + 554 + 41 + 5 = 666.

It is not a de Polignac number, because 20856554415 - 2¹ = 20856554413 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20856554413) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 380154 + ... + 431543.

It is an arithmetic number, because the mean of its divisors is an integer number (1508946582).

Almost surely, 2^20856554415 is an apocalyptic number.

20856554415 is a deficient number, since it is larger than the sum of its proper divisors (15358163553).

20856554415 is a wasteful number, since it uses less digits than its factorization.

20856554415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 812279 (or 812276 counting only the distinct ones).

The product of its (nonzero) digits is 960000, while the sum is 45.

The spelling of 20856554415 in words is "twenty billion, eight hundred fifty-six million, five hundred fifty-four thousand, four hundred fifteen".