21214064266421 has 4 divisors (see below), whose sum is σ = 22845915363852. Its totient is φ = 19582213168992.

The previous prime is 21214064266391. The next prime is 21214064266429. The reversal of 21214064266421 is 12466246041212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8493500038321 + 12720564228100 = 2914361^2 + 3566590^2 .

It is a cyclic number.

It is not a de Polignac number, because 21214064266421 - 2³⁸ = 20939186359477 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 (21214064266429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 815925548696 + ... + 815925548721.

It is an arithmetic number, because the mean of its divisors is an integer number (5711478840963).

Almost surely, 2^{21214064266421} is an apocalyptic number.

It is an amenable number.

21214064266421 is a deficient number, since it is larger than the sum of its proper divisors (1631851097431).

21214064266421 is a wasteful number, since it uses less digits than its factorization.

21214064266421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631851097430.

The product of its (nonzero) digits is 221184, while the sum is 41.

The spelling of 21214064266421 in words is "twenty-one trillion, two hundred fourteen billion, sixty-four million, two hundred sixty-six thousand, four hundred twenty-one".