91872225 has 63 divisors (see below), whose sum is σ = 173243779. Its totient is φ = 48308400.

The previous prime is 91872217. The next prime is 91872227. The reversal of 91872225 is 52227819.

The square root of 91872225 is 9585.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 33074001 + 58798224 = 5751^2 + 7668^2 .

It is not a de Polignac number, because 91872225 - 2³ = 91872217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91872225.

It is not an unprimeable number, because it can be changed into a prime (91872227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 1293940 + ... + 1294010.

Almost surely, 2^91872225 is an apocalyptic number.

91872225 is the 9585-th square number.

91872225 is the 4793-rd centered octagonal number.

It is an amenable number.

91872225 is a deficient number, since it is larger than the sum of its proper divisors (81371554).

91872225 is an frugal number, since it uses more digits than its factorization.

91872225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 79 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The cubic root of 91872225 is about 451.2266532326.

Multiplying 91872225 by its sum of digits (36), we get a square (3307400100 = 57510²).

The spelling of 91872225 in words is "ninety-one million, eight hundred seventy-two thousand, two hundred twenty-five".