651561656166 has 48 divisors (see below), whose sum is σ = 1425848576256. Its totient is φ = 215014378608.

The previous prime is 651561656143. The next prime is 651561656177. The reversal of 651561656166 is 661656165156.

651561656166 is a `hidden beast` number, since 6 + 5 + 1 + 5 + 6 + 16 + 5 + 616 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6369661 + ... + 6471143.

It is an arithmetic number, because the mean of its divisors is an integer number (29705178672).

Almost surely, 2^651561656166 is an apocalyptic number.

651561656166 is an abundant number, since it is smaller than the sum of its proper divisors (774286920090).

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

651561656166 is a wasteful number, since it uses less digits than its factorization.

651561656166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105057 (or 105054 counting only the distinct ones).

The product of its digits is 5832000, while the sum is 54.

The spelling of 651561656166 in words is "six hundred fifty-one billion, five hundred sixty-one million, six hundred fifty-six thousand, one hundred sixty-six".