91987085 has 32 divisors (see below), whose sum is σ = 120608352. Its totient is φ = 67092480.

The previous prime is 91987061. The next prime is 91987109. The reversal of 91987085 is 58078919.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (91987061) and next prime (91987109).

It can be written as a sum of positive squares in 16 ways, for example, as 69272329 + 22714756 = 8323^2 + 4766^2 .

It is a de Polignac number, because none of the positive numbers 2^k-91987085 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 585827 + ... + 585983.

It is an arithmetic number, because the mean of its divisors is an integer number (3769011).

Almost surely, 2^91987085 is an apocalyptic number.

It is an amenable number.

91987085 is a deficient number, since it is larger than the sum of its proper divisors (28621267).

91987085 is a wasteful number, since it uses less digits than its factorization.

91987085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353.

The product of its (nonzero) digits is 181440, while the sum is 47.

The square root of 91987085 is about 9590.9897820819. The cubic root of 91987085 is about 451.4146183102.

The spelling of 91987085 in words is "ninety-one million, nine hundred eighty-seven thousand, eighty-five".