91578481 has 4 divisors (see below), whose sum is σ = 92945392. Its totient is φ = 90211572.

The previous prime is 91578469. The next prime is 91578497. The reversal of 91578481 is 18487519.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 91578481 - 2⁷ = 91578353 is a prime.

It is a super-2 number, since 2×91578481² = 16773236364534722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91578451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 683355 + ... + 683488.

It is an arithmetic number, because the mean of its divisors is an integer number (23236348).

Almost surely, 2^91578481 is an apocalyptic number.

It is an amenable number.

91578481 is a deficient number, since it is larger than the sum of its proper divisors (1366911).

91578481 is a wasteful number, since it uses less digits than its factorization.

91578481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1366910.

The product of its digits is 80640, while the sum is 43.

The square root of 91578481 is about 9569.6646231725. The cubic root of 91578481 is about 450.7452359304.

The spelling of 91578481 in words is "ninety-one million, five hundred seventy-eight thousand, four hundred eighty-one".