661725522 has 12 divisors (see below), whose sum is σ = 1433738670. Its totient is φ = 220575168.

The previous prime is 661725503. The next prime is 661725523. The reversal of 661725522 is 225527166.

661725522 is a `hidden beast` number, since 6 + 61 + 72 + 5 + 522 = 666.

It can be written as a sum of positive squares in only one way, i.e., 549386721 + 112338801 = 23439^2 + 10599^2 .

It is not an unprimeable number, because it can be changed into a prime (661725523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18381247 + ... + 18381282.

Almost surely, 2^661725522 is an apocalyptic number.

661725522 is an abundant number, since it is smaller than the sum of its proper divisors (772013148).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661725522 is a wasteful number, since it uses less digits than its factorization.

661725522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36762537 (or 36762534 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The square root of 661725522 is about 25724.0261623254. The cubic root of 661725522 is about 871.4168668473.

The spelling of 661725522 in words is "six hundred sixty-one million, seven hundred twenty-five thousand, five hundred twenty-two".