691427025 has 27 divisors (see below), whose sum is σ = 1239129489. Its totient is φ = 368550720.

The previous prime is 691427017. The next prime is 691427047. The reversal of 691427025 is 520724196.

The square root of 691427025 is 26295.

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

691427025 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 326922561 + 364504464 = 18081^2 + 19092^2 .

It is not a de Polignac number, because 691427025 - 2³ = 691427017 is a prime.

It is a Curzon 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, 393549 + ... + 395301.

Almost surely, 2^691427025 is an apocalyptic number.

691427025 is the 26295-th square number.

691427025 is the 13148-th centered octagonal number.

It is an amenable number.

691427025 is a deficient number, since it is larger than the sum of its proper divisors (547702464).

691427025 is an equidigital number, since it uses as much as digits as its factorization.

691427025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3522 (or 1761 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The cubic root of 691427025 is about 884.2643508426.

Multiplying 691427025 by its sum of digits (36), we get a square (24891372900 = 157770²).

It can be divided in two parts, 69142 and 7025, that added together give a palindrome (76167).

The spelling of 691427025 in words is "six hundred ninety-one million, four hundred twenty-seven thousand, twenty-five".