87616721565 has 48 divisors (see below), whose sum is σ = 152460899136. Its totient is φ = 46547136000.

The previous prime is 87616721551. The next prime is 87616721579. The reversal of 87616721565 is 56512761678.

It is a happy number.

87616721565 is a `hidden beast` number, since 8 + 7 + 6 + 1 + 6 + 72 + 1 + 565 = 666.

It is an interprime number because it is at equal distance from previous prime (87616721551) and next prime (87616721579).

It is not a de Polignac number, because 87616721565 - 2⁹ = 87616721053 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14631502 + ... + 14637488.

It is an arithmetic number, because the mean of its divisors is an integer number (3176268732).

Almost surely, 2^87616721565 is an apocalyptic number.

It is an amenable number.

87616721565 is a deficient number, since it is larger than the sum of its proper divisors (64844177571).

87616721565 is a wasteful number, since it uses less digits than its factorization.

87616721565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7210 (or 7207 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 54.

The spelling of 87616721565 in words is "eighty-seven billion, six hundred sixteen million, seven hundred twenty-one thousand, five hundred sixty-five".