91015625 has 18 divisors (see below), whose sum is σ = 114257754. Its totient is φ = 72500000.

The previous prime is 91015571. The next prime is 91015627. The reversal of 91015625 is 52651019.

It can be written as a sum of positive squares in 9 ways, for example, as 17330569 + 73685056 = 4163^2 + 8584^2 .

It is not a de Polignac number, because 91015625 - 2²⁰ = 89967049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91015627) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 390509 + ... + 390741.

It is an arithmetic number, because the mean of its divisors is an integer number (6347653).

Almost surely, 2^91015625 is an apocalyptic number.

It is an amenable number.

91015625 is a deficient number, since it is larger than the sum of its proper divisors (23242129).

91015625 is an frugal number, since it uses more digits than its factorization.

91015625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273 (or 238 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 29.

The square root of 91015625 is about 9540.2109515461. The cubic root of 91015625 is about 449.8198867667.

The spelling of 91015625 in words is "ninety-one million, fifteen thousand, six hundred twenty-five".