661957759166 has 16 divisors (see below), whose sum is σ = 1085148336240. Its totient is φ = 300349687680.

The previous prime is 661957759163. The next prime is 661957759271.

661957759166 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 661957759096 and 661957759105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661957759163) 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, 26997611 + ... + 27022118.

It is an arithmetic number, because the mean of its divisors is an integer number (67821771015).

Almost surely, 2^661957759166 is an apocalyptic number.

661957759166 is a deficient number, since it is larger than the sum of its proper divisors (423190577074).

661957759166 is a wasteful number, since it uses less digits than its factorization.

661957759166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54020299.

The product of its digits is 128595600, while the sum is 68.

The spelling of 661957759166 in words is "six hundred sixty-one billion, nine hundred fifty-seven million, seven hundred fifty-nine thousand, one hundred sixty-six".