661522605 has 16 divisors (see below), whose sum is σ = 1063063680. Its totient is φ = 351269568.

The previous prime is 661522591. The next prime is 661522607. The reversal of 661522605 is 506225166.

It is a happy number.

661522605 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 661522605 - 2⁸ = 661522349 is a prime.

It is a super-2 number, since 2×661522605² = 875224313851972050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661522607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92857 + ... + 99726.

It is an arithmetic number, because the mean of its divisors is an integer number (66441480).

Almost surely, 2^661522605 is an apocalyptic number.

It is an amenable number.

661522605 is a deficient number, since it is larger than the sum of its proper divisors (401541075).

661522605 is a wasteful number, since it uses less digits than its factorization.

661522605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192820.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 661522605 is about 25720.0817455933. The cubic root of 661522605 is about 871.3277849103.

The spelling of 661522605 in words is "six hundred sixty-one million, five hundred twenty-two thousand, six hundred five".