87617989 has 2 divisors, whose sum is σ = 87617990. Its totient is φ = 87617988.

The previous prime is 87617969. The next prime is 87618023. The reversal of 87617989 is 98971678.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83448225 + 4169764 = 9135^2 + 2042^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87617989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87617969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43808994 + 43808995.

It is an arithmetic number, because the mean of its divisors is an integer number (43808995).

Almost surely, 2^87617989 is an apocalyptic number.

It is an amenable number.

87617989 is a deficient number, since it is larger than the sum of its proper divisors (1).

87617989 is an equidigital number, since it uses as much as digits as its factorization.

87617989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 55.

The square root of 87617989 is about 9360.4481196148. The cubic root of 87617989 is about 444.1514596360.

The spelling of 87617989 in words is "eighty-seven million, six hundred seventeen thousand, nine hundred eighty-nine".