87911591 has 2 divisors, whose sum is σ = 87911592. Its totient is φ = 87911590.

The previous prime is 87911581. The next prime is 87911617. The reversal of 87911591 is 19511978.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87911591 - 2¹⁴ = 87895207 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87911581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43955795 + 43955796.

It is an arithmetic number, because the mean of its divisors is an integer number (43955796).

Almost surely, 2^87911591 is an apocalyptic number.

87911591 is a deficient number, since it is larger than the sum of its proper divisors (1).

87911591 is an equidigital number, since it uses as much as digits as its factorization.

87911591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 41.

The square root of 87911591 is about 9376.1181199897. The cubic root of 87911591 is about 444.6470137675.

The spelling of 87911591 in words is "eighty-seven million, nine hundred eleven thousand, five hundred ninety-one".