91509725 has 12 divisors (see below), whose sum is σ = 120147444. Its totient is φ = 68901120.

The previous prime is 91509707. The next prime is 91509791. The reversal of 91509725 is 52790519.

It can be written as a sum of positive squares in 6 ways, for example, as 7365796 + 84143929 = 2714^2 + 9173^2 .

It is not a de Polignac number, because 91509725 - 2¹⁶ = 91444189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107234 + ... + 108083.

It is an arithmetic number, because the mean of its divisors is an integer number (10012287).

Almost surely, 2^91509725 is an apocalyptic number.

It is an amenable number.

91509725 is a deficient number, since it is larger than the sum of its proper divisors (28637719).

91509725 is a wasteful number, since it uses less digits than its factorization.

91509725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215344 (or 215339 counting only the distinct ones).

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

The square root of 91509725 is about 9566.0715552415. The cubic root of 91509725 is about 450.6324030234.

The spelling of 91509725 in words is "ninety-one million, five hundred nine thousand, seven hundred twenty-five".