87561657 has 24 divisors (see below), whose sum is σ = 129201800. Its totient is φ = 57127680.

The previous prime is 87561653. The next prime is 87561689. The reversal of 87561657 is 75616578.

87561657 is a `hidden beast` number, since 87 + 561 + 6 + 5 + 7 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 14356521 + 73205136 = 3789^2 + 8556^2 .

It is not a de Polignac number, because 87561657 - 2² = 87561653 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87561653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 191373 + ... + 191829.

Almost surely, 2^87561657 is an apocalyptic number.

It is an amenable number.

87561657 is a deficient number, since it is larger than the sum of its proper divisors (41640143).

87561657 is a wasteful number, since it uses less digits than its factorization.

87561657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873 (or 870 counting only the distinct ones).

The product of its digits is 352800, while the sum is 45.

The square root of 87561657 is about 9357.4385918370. The cubic root of 87561657 is about 444.0562535251.

The spelling of 87561657 in words is "eighty-seven million, five hundred sixty-one thousand, six hundred fifty-seven".