91087749 has 12 divisors (see below), whose sum is σ = 131656876. Its totient is φ = 60685632.

The previous prime is 91087699. The next prime is 91087757. The reversal of 91087749 is 94778019.

It can be written as a sum of positive squares in 2 ways, for example, as 39463524 + 51624225 = 6282^2 + 7185^2 .

It is not a de Polignac number, because 91087749 - 2²⁵ = 57533317 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 (91087949) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19857 + ... + 24009.

Almost surely, 2^91087749 is an apocalyptic number.

It is an amenable number.

91087749 is a deficient number, since it is larger than the sum of its proper divisors (40569127).

91087749 is a wasteful number, since it uses less digits than its factorization.

91087749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6596 (or 6593 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The square root of 91087749 is about 9543.9902032640. The cubic root of 91087749 is about 449.9386731241.

The spelling of 91087749 in words is "ninety-one million, eighty-seven thousand, seven hundred forty-nine".