21523404144001 has 4 divisors (see below), whose sum is σ = 21551248134612. Its totient is φ = 21495560153392.

The previous prime is 21523404143977. The next prime is 21523404144043. The reversal of 21523404144001 is 10044140432512.

It is a happy number.

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 8178593310976 + 13344810833025 = 2859824^2 + 3653055^2 .

It is a cyclic number.

It is not a de Polignac number, because 21523404144001 - 2²⁷ = 21523269926273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21523404144101) 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, 13921994146 + ... + 13921995691.

It is an arithmetic number, because the mean of its divisors is an integer number (5387812033653).

Almost surely, 2^{21523404144001} is an apocalyptic number.

It is an amenable number.

21523404144001 is a deficient number, since it is larger than the sum of its proper divisors (27843990611).

21523404144001 is an equidigital number, since it uses as much as digits as its factorization.

21523404144001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27843990610.

The product of its (nonzero) digits is 15360, while the sum is 31.

Adding to 21523404144001 its reverse (10044140432512), we get a palindrome (31567544576513).

The spelling of 21523404144001 in words is "twenty-one trillion, five hundred twenty-three billion, four hundred four million, one hundred forty-four thousand, one".