2661345651664 has 20 divisors (see below), whose sum is σ = 5892979657504. Its totient is φ = 1140576707808.

The previous prime is 2661345651641. The next prime is 2661345651691. The reversal of 2661345651664 is 4661565431662.

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 3 ways as a sum of consecutive naturals, for example, 11881007262 + ... + 11881007485.

Almost surely, 2^{2661345651664} is an apocalyptic number.

It is an amenable number.

2661345651664 is an abundant number, since it is smaller than the sum of its proper divisors (3231634005840).

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

2661345651664 is a wasteful number, since it uses less digits than its factorization.

2661345651664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23762014762 (or 23762014756 counting only the distinct ones).

The product of its digits is 18662400, while the sum is 55.

The spelling of 2661345651664 in words is "two trillion, six hundred sixty-one billion, three hundred forty-five million, six hundred fifty-one thousand, six hundred sixty-four".