21404144023 has 4 divisors (see below), whose sum is σ = 21982634440. Its totient is φ = 20825653608.

The previous prime is 21404143991. The next prime is 21404144033. The reversal of 21404144023 is 32044140412.

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

It is a cyclic number.

It is not a de Polignac number, because 21404144023 - 2⁵ = 21404143991 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 (21404144033) 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, 289245153 + ... + 289245226.

It is an arithmetic number, because the mean of its divisors is an integer number (5495658610).

Almost surely, 2^21404144023 is an apocalyptic number.

21404144023 is a deficient number, since it is larger than the sum of its proper divisors (578490417).

21404144023 is an equidigital number, since it uses as much as digits as its factorization.

21404144023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578490416.

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21404144023 its reverse (32044140412), we get a palindrome (53448284435).

It can be divided in two parts, 214041 and 44023, that added together give a square (258064 = 508²).

The spelling of 21404144023 in words is "twenty-one billion, four hundred four million, one hundred forty-four thousand, twenty-three".