91019873025 has 27 divisors (see below), whose sum is σ = 163034811849. Its totient is φ = 48541518720.

The previous prime is 91019873003. The next prime is 91019873039. The reversal of 91019873025 is 52037891019.

The square root of 91019873025 is 301695.

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

It can be written as a sum of positive squares in 4 ways, for example, as 35751624561 + 55268248464 = 189081^2 + 235092^2 .

It is not a de Polignac number, because 91019873025 - 2⁹ = 91019872513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4515369 + ... + 4535481.

Almost surely, 2^91019873025 is an apocalyptic number.

91019873025 is the 301695-th square number.

91019873025 is the 150848-th centered octagonal number.

It is an amenable number.

91019873025 is a deficient number, since it is larger than the sum of its proper divisors (72014938824).

91019873025 is an frugal number, since it uses more digits than its factorization.

91019873025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40242 (or 20121 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The spelling of 91019873025 in words is "ninety-one billion, nineteen million, eight hundred seventy-three thousand, twenty-five".