21144291914921 has 24 divisors (see below), whose sum is σ = 24891140851200. Its totient is φ = 17907790639200.

The previous prime is 21144291914873. The next prime is 21144291914951. The reversal of 21144291914921 is 12941919244112.

It is not a de Polignac number, because 21144291914921 - 2¹⁴ = 21144291898537 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21144291914921.

It is not an unprimeable number, because it can be changed into a prime (21144291914951) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6186875 + ... + 8975856.

It is an arithmetic number, because the mean of its divisors is an integer number (1037130868800).

Almost surely, 2^{21144291914921} is an apocalyptic number.

It is an amenable number.

21144291914921 is a deficient number, since it is larger than the sum of its proper divisors (3746848936279).

21144291914921 is a wasteful number, since it uses less digits than its factorization.

21144291914921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15163085 (or 15163078 counting only the distinct ones).

The product of its digits is 373248, while the sum is 50.

The spelling of 21144291914921 in words is "twenty-one trillion, one hundred forty-four billion, two hundred ninety-one million, nine hundred fourteen thousand, nine hundred twenty-one".