91641887 has 4 divisors (see below), whose sum is σ = 91822440. Its totient is φ = 91461336.

The previous prime is 91641841. The next prime is 91641899. The reversal of 91641887 is 78814619.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91641887 - 2¹⁴ = 91625503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91641287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89513 + ... + 90530.

It is an arithmetic number, because the mean of its divisors is an integer number (22955610).

Almost surely, 2^91641887 is an apocalyptic number.

91641887 is a deficient number, since it is larger than the sum of its proper divisors (180553).

91641887 is a wasteful number, since it uses less digits than its factorization.

91641887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180552.

The product of its digits is 96768, while the sum is 44.

The square root of 91641887 is about 9572.9769142101. The cubic root of 91641887 is about 450.8492391078.

The spelling of 91641887 in words is "ninety-one million, six hundred forty-one thousand, eight hundred eighty-seven".