91481787 has 24 divisors (see below), whose sum is σ = 140834304. Its totient is φ = 57088944.

The previous prime is 91481773. The next prime is 91481809. The reversal of 91481787 is 78718419.

91481787 is a `hidden beast` number, since 91 + 481 + 7 + 87 = 666.

It is not a de Polignac number, because 91481787 - 2⁸ = 91481531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91481707) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5028 + ... + 14430.

It is an arithmetic number, because the mean of its divisors is an integer number (5868096).

Almost surely, 2^91481787 is an apocalyptic number.

91481787 is a deficient number, since it is larger than the sum of its proper divisors (49352517).

91481787 is a wasteful number, since it uses less digits than its factorization.

91481787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9479 (or 9476 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The square root of 91481787 is about 9564.6111787150. The cubic root of 91481787 is about 450.5865388652.

The spelling of 91481787 in words is "ninety-one million, four hundred eighty-one thousand, seven hundred eighty-seven".