91561473 has 24 divisors (see below), whose sum is σ = 140493600. Its totient is φ = 57262464.

The previous prime is 91561471. The next prime is 91561511. The reversal of 91561473 is 37416519.

91561473 is a `hidden beast` number, since 91 + 561 + 4 + 7 + 3 = 666.

It is not a de Polignac number, because 91561473 - 2¹ = 91561471 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91561471) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57198 + ... + 58776.

It is an arithmetic number, because the mean of its divisors is an integer number (5853900).

Almost surely, 2^91561473 is an apocalyptic number.

It is an amenable number.

91561473 is a deficient number, since it is larger than the sum of its proper divisors (48932127).

91561473 is a wasteful number, since it uses less digits than its factorization.

91561473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1981 (or 1978 counting only the distinct ones).

The product of its digits is 22680, while the sum is 36.

The square root of 91561473 is about 9568.7759405266. The cubic root of 91561473 is about 450.7173299947.

The spelling of 91561473 in words is "ninety-one million, five hundred sixty-one thousand, four hundred seventy-three".