661679792959 has 4 divisors (see below), whose sum is σ = 696505045240. Its totient is φ = 626854540680.

The previous prime is 661679792941. The next prime is 661679793079. The reversal of 661679792959 is 959297976166.

661679792959 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 661679792959 - 2⁷ = 661679792831 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661679792659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17412626112 + ... + 17412626149.

It is an arithmetic number, because the mean of its divisors is an integer number (174126261310).

Almost surely, 2^661679792959 is an apocalyptic number.

661679792959 is a deficient number, since it is larger than the sum of its proper divisors (34825252281).

661679792959 is a wasteful number, since it uses less digits than its factorization.

661679792959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34825252280.

The product of its digits is 694416240, while the sum is 76.

The spelling of 661679792959 in words is "six hundred sixty-one billion, six hundred seventy-nine million, seven hundred ninety-two thousand, nine hundred fifty-nine".