21440202023 has 4 divisors (see below), whose sum is σ = 21498622560. Its totient is φ = 21381781488.

The previous prime is 21440201987. The next prime is 21440202029. The reversal of 21440202023 is 32020204412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21440202023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21440201986 and 21440202004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440202029) 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, 29209718 + ... + 29210451.

It is an arithmetic number, because the mean of its divisors is an integer number (5374655640).

Almost surely, 2^21440202023 is an apocalyptic number.

21440202023 is a deficient number, since it is larger than the sum of its proper divisors (58420537).

21440202023 is an equidigital number, since it uses as much as digits as its factorization.

21440202023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58420536.

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 21440202023 its reverse (32020204412), we get a palindrome (53460406435).

It can be divided in two parts, 21 and 440202023, that added together give a palindrome (440202044).

The spelling of 21440202023 in words is "twenty-one billion, four hundred forty million, two hundred two thousand, twenty-three".