91864477 has 4 divisors (see below), whose sum is σ = 94105116. Its totient is φ = 89623840.

The previous prime is 91864471. The next prime is 91864517. The reversal of 91864477 is 77446819.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 77446819 = 23 ⋅3367253.

It can be written as a sum of positive squares in 2 ways, for example, as 15634116 + 76230361 = 3954^2 + 8731^2 .

It is a cyclic number.

It is not a de Polignac number, because 91864477 - 2⁷ = 91864349 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 (91864471) 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, 1120258 + ... + 1120339.

It is an arithmetic number, because the mean of its divisors is an integer number (23526279).

Almost surely, 2^91864477 is an apocalyptic number.

It is an amenable number.

91864477 is a deficient number, since it is larger than the sum of its proper divisors (2240639).

91864477 is a wasteful number, since it uses less digits than its factorization.

91864477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2240638.

The product of its digits is 338688, while the sum is 46.

The square root of 91864477 is about 9584.5958182909. The cubic root of 91864477 is about 451.2139682149.

The spelling of 91864477 in words is "ninety-one million, eight hundred sixty-four thousand, four hundred seventy-seven".