661887208674 has 32 divisors (see below), whose sum is σ = 1474803834240. Its totient is φ = 220037564016.

The previous prime is 661887208657. The next prime is 661887208699. The reversal of 661887208674 is 476802788166.

661887208674 is a `hidden beast` number, since 6 + 618 + 8 + 7 + 2 + 0 + 8 + 6 + 7 + 4 = 666.

It is an unprimeable number.

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, 16410382 + ... + 16450665.

It is an arithmetic number, because the mean of its divisors is an integer number (46087619820).

Almost surely, 2^661887208674 is an apocalyptic number.

661887208674 is an abundant number, since it is smaller than the sum of its proper divisors (812916625566).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661887208674 is a wasteful number, since it uses less digits than its factorization.

661887208674 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32861431 (or 32861425 counting only the distinct ones).

The product of its (nonzero) digits is 43352064, while the sum is 63.

The spelling of 661887208674 in words is "six hundred sixty-one billion, eight hundred eighty-seven million, two hundred eight thousand, six hundred seventy-four".