87513661 has 4 divisors (see below), whose sum is σ = 87579324. Its totient is φ = 87448000.

The previous prime is 87513659. The next prime is 87513667. The reversal of 87513661 is 16631578.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16631578 = 2 ⋅8315789.

It can be written as a sum of positive squares in 2 ways, for example, as 22146436 + 65367225 = 4706^2 + 8085^2 .

It is a cyclic number.

It is not a de Polignac number, because 87513661 - 2¹ = 87513659 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 87513661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87513667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30790 + ... + 33511.

It is an arithmetic number, because the mean of its divisors is an integer number (21894831).

Almost surely, 2^87513661 is an apocalyptic number.

It is an amenable number.

87513661 is a deficient number, since it is larger than the sum of its proper divisors (65663).

87513661 is a wasteful number, since it uses less digits than its factorization.

87513661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65662.

The product of its digits is 30240, while the sum is 37.

The square root of 87513661 is about 9354.8736496010. The cubic root of 87513661 is about 443.9751037768.

The spelling of 87513661 in words is "eighty-seven million, five hundred thirteen thousand, six hundred sixty-one".