91887961 has 16 divisors (see below), whose sum is σ = 103576320. Its totient is φ = 80798080.

The previous prime is 91887949. The next prime is 91887973. The reversal of 91887961 is 16978819.

It is an interprime number because it is at equal distance from previous prime (91887949) and next prime (91887973).

It is not a de Polignac number, because 91887961 - 2⁷ = 91887833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91887911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45015 + ... + 47011.

It is an arithmetic number, because the mean of its divisors is an integer number (6473520).

Almost surely, 2^91887961 is an apocalyptic number.

It is an amenable number.

91887961 is a deficient number, since it is larger than the sum of its proper divisors (11688359).

91887961 is a wasteful number, since it uses less digits than its factorization.

91887961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2144.

The product of its digits is 217728, while the sum is 49.

The square root of 91887961 is about 9585.8208307896. The cubic root of 91887961 is about 451.2524140007.

The spelling of 91887961 in words is "ninety-one million, eight hundred eighty-seven thousand, nine hundred sixty-one".