91972505 has 12 divisors (see below), whose sum is σ = 114048036. Its totient is φ = 71200800.

The previous prime is 91972501. The next prime is 91972513. The reversal of 91972505 is 50527919.

It can be written as a sum of positive squares in 2 ways, for example, as 41576704 + 50395801 = 6448^2 + 7099^2 .

It is not a de Polignac number, because 91972505 - 2² = 91972501 is a prime.

It is a super-3 number, since 3×91972505³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91972501) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4766 + ... + 14375.

It is an arithmetic number, because the mean of its divisors is an integer number (9504003).

Almost surely, 2^91972505 is an apocalyptic number.

It is an amenable number.

91972505 is a deficient number, since it is larger than the sum of its proper divisors (22075531).

91972505 is a wasteful number, since it uses less digits than its factorization.

91972505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19208 (or 19177 counting only the distinct ones).

The product of its (nonzero) digits is 28350, while the sum is 38.

The square root of 91972505 is about 9590.2296635691. The cubic root of 91972505 is about 451.3907672341.

The spelling of 91972505 in words is "ninety-one million, nine hundred seventy-two thousand, five hundred five".