6561500157 has 6 divisors (see below), whose sum is σ = 9477722462. Its totient is φ = 4374333432.

The previous prime is 6561500137. The next prime is 6561500159. The reversal of 6561500157 is 7510051656.

It can be written as a sum of positive squares in only one way, i.e., 4134361401 + 2427138756 = 64299^2 + 49266^2 .

It is not a de Polignac number, because 6561500157 - 2¹² = 6561496061 is a prime.

It is a super-2 number, since 2×6561500157² = 86106568620622049298, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561500159) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 364527778 + ... + 364527795.

Almost surely, 2^6561500157 is an apocalyptic number.

It is an amenable number.

6561500157 is a deficient number, since it is larger than the sum of its proper divisors (2916222305).

6561500157 is a wasteful number, since it uses less digits than its factorization.

6561500157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 729055579 (or 729055576 counting only the distinct ones).

The product of its (nonzero) digits is 31500, while the sum is 36.

The square root of 6561500157 is about 81003.0873300518. The cubic root of 6561500157 is about 1872.1230101134.

The spelling of 6561500157 in words is "six billion, five hundred sixty-one million, five hundred thousand, one hundred fifty-seven".