661660689711 has 32 divisors (see below), whose sum is σ = 1013473152000. Its totient is φ = 376131824640.

The previous prime is 661660689709. The next prime is 661660689869. The reversal of 661660689711 is 117986066166.

It is not a de Polignac number, because 661660689711 - 2¹ = 661660689709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661660681711) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 48005641 + ... + 48019421.

It is an arithmetic number, because the mean of its divisors is an integer number (31671036000).

Almost surely, 2^661660689711 is an apocalyptic number.

661660689711 is a deficient number, since it is larger than the sum of its proper divisors (351812462289).

661660689711 is a wasteful number, since it uses less digits than its factorization.

661660689711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25479.

The product of its (nonzero) digits is 3919104, while the sum is 57.

The spelling of 661660689711 in words is "six hundred sixty-one billion, six hundred sixty million, six hundred eighty-nine thousand, seven hundred eleven".