21162650642551 has 16 divisors (see below), whose sum is σ = 25731114773760. Its totient is φ = 17154076510080.

The previous prime is 21162650642527. The next prime is 21162650642603. The reversal of 21162650642551 is 15524605626112.

It is a cyclic number.

It is not a de Polignac number, because 21162650642551 - 2¹¹ = 21162650640503 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21162650642851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2978134731 + ... + 2978141836.

It is an arithmetic number, because the mean of its divisors is an integer number (1608194673360).

Almost surely, 2^{21162650642551} is an apocalyptic number.

21162650642551 is a deficient number, since it is larger than the sum of its proper divisors (4568464131209).

21162650642551 is a wasteful number, since it uses less digits than its factorization.

21162650642551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5956276614.

The product of its (nonzero) digits is 864000, while the sum is 46.

The spelling of 21162650642551 in words is "twenty-one trillion, one hundred sixty-two billion, six hundred fifty million, six hundred forty-two thousand, five hundred fifty-one".