691745225 has 6 divisors (see below), whose sum is σ = 857764110. Its totient is φ = 553396160.

The previous prime is 691745221. The next prime is 691745227. The reversal of 691745225 is 522547196.

691745225 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 3 ways, for example, as 243110464 + 448634761 = 15592^2 + 21181^2 .

It is not a de Polignac number, because 691745225 - 2² = 691745221 is a prime.

It is a super-2 number, since 2×691745225² = 957022912620601250, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (691745221) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13834880 + ... + 13834929.

It is an arithmetic number, because the mean of its divisors is an integer number (142960685).

Almost surely, 2^691745225 is an apocalyptic number.

It is an amenable number.

691745225 is a deficient number, since it is larger than the sum of its proper divisors (166018885).

691745225 is a wasteful number, since it uses less digits than its factorization.

691745225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27669819 (or 27669814 counting only the distinct ones).

The product of its digits is 151200, while the sum is 41.

The square root of 691745225 is about 26301.0498839875. The cubic root of 691745225 is about 884.3999784427.

The spelling of 691745225 in words is "six hundred ninety-one million, seven hundred forty-five thousand, two hundred twenty-five".