21162650641661 has 12 divisors (see below), whose sum is σ = 21885761817216. Its totient is φ = 20462729821560.

The previous prime is 21162650641547. The next prime is 21162650641669. The reversal of 21162650641661 is 16614605626112.

It is a de Polignac number, because none of the positive numbers 2^k-21162650641661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21162650641669) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 8135405 + ... + 10416818.

It is an arithmetic number, because the mean of its divisors is an integer number (1823813484768).

Almost surely, 2^{21162650641661} is an apocalyptic number.

It is an amenable number.

21162650641661 is a deficient number, since it is larger than the sum of its proper divisors (723111175555).

21162650641661 is a wasteful number, since it uses less digits than its factorization.

21162650641661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18553472 (or 18553441 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 21162650641661 in words is "twenty-one trillion, one hundred sixty-two billion, six hundred fifty million, six hundred forty-one thousand, six hundred sixty-one".