91897569 has 6 divisors (see below), whose sum is σ = 132740946. Its totient is φ = 61265040.

The previous prime is 91897567. The next prime is 91897591. The reversal of 91897569 is 96579819.

It can be written as a sum of positive squares in only one way, i.e., 52056225 + 39841344 = 7215^2 + 6312^2 .

It is not a de Polignac number, because 91897569 - 2¹ = 91897567 is a prime.

It is a super-2 number, since 2×91897569² = 16890326376219522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91897567) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5105412 + ... + 5105429.

It is an arithmetic number, because the mean of its divisors is an integer number (22123491).

Almost surely, 2^91897569 is an apocalyptic number.

It is an amenable number.

91897569 is a deficient number, since it is larger than the sum of its proper divisors (40843377).

91897569 is a wasteful number, since it uses less digits than its factorization.

91897569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10210847 (or 10210844 counting only the distinct ones).

The product of its digits is 1224720, while the sum is 54.

The square root of 91897569 is about 9586.3219745635. The cubic root of 91897569 is about 451.2681414222.

The spelling of 91897569 in words is "ninety-one million, eight hundred ninety-seven thousand, five hundred sixty-nine".