661208238879 has 8 divisors (see below), whose sum is σ = 933470454960. Its totient is φ = 414875757696.

The previous prime is 661208238839. The next prime is 661208238883. The reversal of 661208238879 is 978832802166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661208238879 - 2¹⁵ = 661208206111 is a prime.

It is a super-2 number, since 2×661208238879² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661208238829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6482433664 + ... + 6482433765.

It is an arithmetic number, because the mean of its divisors is an integer number (116683806870).

Almost surely, 2^661208238879 is an apocalyptic number.

661208238879 is a deficient number, since it is larger than the sum of its proper divisors (272262216081).

661208238879 is a wasteful number, since it uses less digits than its factorization.

661208238879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12964867449.

The product of its (nonzero) digits is 13934592, while the sum is 60.

The spelling of 661208238879 in words is "six hundred sixty-one billion, two hundred eight million, two hundred thirty-eight thousand, eight hundred seventy-nine".