661590523 has 16 divisors (see below), whose sum is σ = 730529280. Its totient is φ = 594151200.

The previous prime is 661590521. The next prime is 661590539. The reversal of 661590523 is 325095166.

It is a cyclic number.

It is not a de Polignac number, because 661590523 - 2¹ = 661590521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661590521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 636238 + ... + 637276.

It is an arithmetic number, because the mean of its divisors is an integer number (45658080).

Almost surely, 2^661590523 is an apocalyptic number.

661590523 is a deficient number, since it is larger than the sum of its proper divisors (68938757).

661590523 is a wasteful number, since it uses less digits than its factorization.

661590523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1698.

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 661590523 is about 25721.4020418794. The cubic root of 661590523 is about 871.3576034002.

The spelling of 661590523 in words is "six hundred sixty-one million, five hundred ninety thousand, five hundred twenty-three".