21401440220421 has 12 divisors (see below), whose sum is σ = 30913281235980. Its totient is φ = 14267585364480.

The previous prime is 21401440220417. The next prime is 21401440220443. The reversal of 21401440220421 is 12402204410412.

21401440220421 is a `hidden beast` number, since 2 + 1 + 4 + 0 + 14 + 4 + 0 + 220 + 421 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13687706096100 + 7713734124321 = 3699690^2 + 2777361^2 .

It is not a de Polignac number, because 21401440220421 - 2² = 21401440220417 is a prime.

It is a super-2 number, since 2×21401440220421² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401440220821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2470 + ... + 6542391.

It is an arithmetic number, because the mean of its divisors is an integer number (2576106769665).

Almost surely, 2^{21401440220421} is an apocalyptic number.

It is an amenable number.

21401440220421 is a deficient number, since it is larger than the sum of its proper divisors (9511841015559).

21401440220421 is a wasteful number, since it uses less digits than its factorization.

21401440220421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6908196 (or 6908193 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 27.

Adding to 21401440220421 its reverse (12402204410412), we get a palindrome (33803644630833).

The spelling of 21401440220421 in words is "twenty-one trillion, four hundred one billion, four hundred forty million, two hundred twenty thousand, four hundred twenty-one".