91403687 has 4 divisors (see below), whose sum is σ = 92308776. Its totient is φ = 90498600.

The previous prime is 91403657. The next prime is 91403701. The reversal of 91403687 is 78630419.

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 91403687 - 2¹⁸ = 91141543 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91403687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91403657) 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, 452393 + ... + 452594.

It is an arithmetic number, because the mean of its divisors is an integer number (23077194).

Almost surely, 2^91403687 is an apocalyptic number.

91403687 is a deficient number, since it is larger than the sum of its proper divisors (905089).

91403687 is a wasteful number, since it uses less digits than its factorization.

91403687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905088.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 91403687 is about 9560.5275482057. The cubic root of 91403687 is about 450.4582771679.

The spelling of 91403687 in words is "ninety-one million, four hundred three thousand, six hundred eighty-seven".