661479659 has 4 divisors (see below), whose sum is σ = 662298120. Its totient is φ = 660661200.

The previous prime is 661479631. The next prime is 661479727. The reversal of 661479659 is 956974166.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 661479659 - 2¹⁶ = 661414123 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661479659.

It is not an unprimeable number, because it can be changed into a prime (661479359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 408017 + ... + 409634.

It is an arithmetic number, because the mean of its divisors is an integer number (165574530).

Almost surely, 2^661479659 is an apocalyptic number.

661479659 is a deficient number, since it is larger than the sum of its proper divisors (818461).

661479659 is an equidigital number, since it uses as much as digits as its factorization.

661479659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 818460.

The product of its digits is 2449440, while the sum is 53.

The square root of 661479659 is about 25719.2468591131. The cubic root of 661479659 is about 871.3089289898.

The spelling of 661479659 in words is "six hundred sixty-one million, four hundred seventy-nine thousand, six hundred fifty-nine".