691716573025 has 27 divisors (see below), whose sum is σ = 863433098073. Its totient is φ = 549717127200.

The previous prime is 691716572909. The next prime is 691716573047. The reversal of 691716573025 is 520375617196.

The square root of 691716573025 is 831695.

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 371242834209 + 320473738816 = 609297^2 + 566104^2 .

It is not a de Polignac number, because 691716573025 - 2²¹ = 691714475873 is a prime.

It is a Duffinian number.

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, 752683516 + ... + 752684434.

Almost surely, 2^691716573025 is an apocalyptic number.

691716573025 is the 831695-th square number.

691716573025 is the 415848-th centered octagonal number.

It is an amenable number.

691716573025 is a deficient number, since it is larger than the sum of its proper divisors (171716525048).

691716573025 is an frugal number, since it uses more digits than its factorization.

691716573025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2210 (or 1105 counting only the distinct ones).

The product of its (nonzero) digits is 2381400, while the sum is 52.

The spelling of 691716573025 in words is "six hundred ninety-one billion, seven hundred sixteen million, five hundred seventy-three thousand, twenty-five".