20551515057 has 24 divisors (see below), whose sum is σ = 30725346600. Its totient is φ = 13221589248.

The previous prime is 20551515043. The next prime is 20551515071. The reversal of 20551515057 is 75051515502.

20551515057 is a `hidden beast` number, since 2 + 0 + 551 + 5 + 1 + 50 + 57 = 666.

It is an interprime number because it is at equal distance from previous prime (20551515043) and next prime (20551515071).

It can be written as a sum of positive squares in 4 ways, for example, as 2734871616 + 17816643441 = 52296^2 + 133479^2 .

It is not a de Polignac number, because 20551515057 - 2¹⁹ = 20550990769 is a prime.

It is a super-2 number, since 2×20551515057² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20551515037) 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, 500419 + ... + 539927.

It is an arithmetic number, because the mean of its divisors is an integer number (1280222775).

Almost surely, 2^20551515057 is an apocalyptic number.

It is an amenable number.

20551515057 is a deficient number, since it is larger than the sum of its proper divisors (10173831543).

20551515057 is a wasteful number, since it uses less digits than its factorization.

20551515057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41537 (or 41534 counting only the distinct ones).

The product of its (nonzero) digits is 43750, while the sum is 36.

The spelling of 20551515057 in words is "twenty billion, five hundred fifty-one million, five hundred fifteen thousand, fifty-seven".