91861481 has 4 divisors (see below), whose sum is σ = 92090964. Its totient is φ = 91632000.

The previous prime is 91861411. The next prime is 91861487. The reversal of 91861481 is 18416819.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 53421481 + 38440000 = 7309^2 + 6200^2 .

It is a cyclic number.

It is not a de Polignac number, because 91861481 - 2¹⁸ = 91599337 is a prime.

It is a super-2 number, since 2×91861481² = 16877063383026722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91861487) 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, 114140 + ... + 114941.

It is an arithmetic number, because the mean of its divisors is an integer number (23022741).

Almost surely, 2^91861481 is an apocalyptic number.

It is an amenable number.

91861481 is a deficient number, since it is larger than the sum of its proper divisors (229483).

91861481 is a wasteful number, since it uses less digits than its factorization.

91861481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229482.

The product of its digits is 13824, while the sum is 38.

The square root of 91861481 is about 9584.4395245627. The cubic root of 91861481 is about 451.2090629755.

The spelling of 91861481 in words is "ninety-one million, eight hundred sixty-one thousand, four hundred eighty-one".