561618157257 has 40 divisors (see below), whose sum is σ = 852881824520. Its totient is φ = 368201687040.

The previous prime is 561618157241. The next prime is 561618157259. The reversal of 561618157257 is 752751816165.

561618157257 is a `hidden beast` number, since 5 + 6 + 1 + 6 + 18 + 1 + 572 + 57 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 6684043536 + 554934113721 = 81756^2 + 744939^2 .

It is not a de Polignac number, because 561618157257 - 2⁴ = 561618157241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561618157259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 38478153 + ... + 38492745.

It is an arithmetic number, because the mean of its divisors is an integer number (21322045613).

Almost surely, 2^561618157257 is an apocalyptic number.

It is an amenable number.

561618157257 is a deficient number, since it is larger than the sum of its proper divisors (291263667263).

561618157257 is a wasteful number, since it uses less digits than its factorization.

561618157257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22455 (or 22446 counting only the distinct ones).

The product of its digits is 3528000, while the sum is 54.

The spelling of 561618157257 in words is "five hundred sixty-one billion, six hundred eighteen million, one hundred fifty-seven thousand, two hundred fifty-seven".