91491025 has 12 divisors (see below), whose sum is σ = 120122892. Its totient is φ = 68887040.

The previous prime is 91491011. The next prime is 91491053. The reversal of 91491025 is 52019419.

It can be written as a sum of positive squares in 6 ways, for example, as 9461776 + 82029249 = 3076^2 + 9057^2 .

It is not a de Polignac number, because 91491025 - 2⁹ = 91490513 is a prime.

It is a Duffinian 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, 107212 + ... + 108061.

It is an arithmetic number, because the mean of its divisors is an integer number (10010241).

Almost surely, 2^91491025 is an apocalyptic number.

It is an amenable number.

91491025 is a deficient number, since it is larger than the sum of its proper divisors (28631867).

91491025 is a wasteful number, since it uses less digits than its factorization.

91491025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215300 (or 215295 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 91491025 is about 9565.0940925848. The cubic root of 91491025 is about 450.6017053753.

The spelling of 91491025 in words is "ninety-one million, four hundred ninety-one thousand, twenty-five".