91872369 has 24 divisors (see below), whose sum is σ = 144317160. Its totient is φ = 56083968.

The previous prime is 91872331. The next prime is 91872371. The reversal of 91872369 is 96327819.

It can be written as a sum of positive squares in 4 ways, for example, as 71622369 + 20250000 = 8463^2 + 4500^2 .

It is not a de Polignac number, because 91872369 - 2⁷ = 91872241 is a prime.

It is a super-2 number, since 2×91872369² = 16881064371344322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91872269) 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, 2454 + ... + 13775.

It is an arithmetic number, because the mean of its divisors is an integer number (6013215).

Almost surely, 2^91872369 is an apocalyptic number.

It is an amenable number.

91872369 is a deficient number, since it is larger than the sum of its proper divisors (52444791).

91872369 is a wasteful number, since it uses less digits than its factorization.

91872369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16289 (or 16286 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 91872369 is about 9585.0075117341. The cubic root of 91872369 is about 451.2268889825.

The spelling of 91872369 in words is "ninety-one million, eight hundred seventy-two thousand, three hundred sixty-nine".