91971925 has 6 divisors (see below), whose sum is σ = 114045218. Its totient is φ = 73577520.

The previous prime is 91971923. The next prime is 91971937. The reversal of 91971925 is 52917919.

It can be written as a sum of positive squares in 3 ways, for example, as 24830289 + 67141636 = 4983^2 + 8194^2 .

It is not a de Polignac number, because 91971925 - 2¹ = 91971923 is a prime.

It is a super-3 number, since 3×91971925³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91971923) 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, 1839414 + ... + 1839463.

Almost surely, 2^91971925 is an apocalyptic number.

It is an amenable number.

91971925 is a deficient number, since it is larger than the sum of its proper divisors (22073293).

91971925 is a wasteful number, since it uses less digits than its factorization.

91971925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3678887 (or 3678882 counting only the distinct ones).

The product of its digits is 51030, while the sum is 43.

The square root of 91971925 is about 9590.1994244124. The cubic root of 91971925 is about 451.3898183737.

It can be divided in two parts, 9197 and 1925, that multiplied together give a triangular number (17704225 = T₅₉₅₀).

The spelling of 91971925 in words is "ninety-one million, nine hundred seventy-one thousand, nine hundred twenty-five".