661818308718662 has 32 divisors (see below), whose sum is σ = 1031934576201984. Its totient is φ = 317995002748800.

The previous prime is 661818308718661. The next prime is 661818308718673. The reversal of 661818308718662 is 266817803818166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661818308718661) 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, 35958893 + ... + 51153480.

It is an arithmetic number, because the mean of its divisors is an integer number (32247955506312).

Almost surely, 2^{661818308718662} is an apocalyptic number.

661818308718662 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

661818308718662 is a deficient number, since it is larger than the sum of its proper divisors (370116267483322).

661818308718662 is a wasteful number, since it uses less digits than its factorization.

661818308718662 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87113264.

The product of its (nonzero) digits is 222953472, while the sum is 71.

The spelling of 661818308718662 in words is "six hundred sixty-one trillion, eight hundred eighteen billion, three hundred eight million, seven hundred eighteen thousand, six hundred sixty-two".