21221525026623 has 4 divisors (see below), whose sum is σ = 28295366702168. Its totient is φ = 14147683351080.

The previous prime is 21221525026607. The next prime is 21221525026649. The reversal of 21221525026623 is 32662052512212.

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

It is not a de Polignac number, because 21221525026623 - 2⁴ = 21221525026607 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 (21221525026693) 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, 3536920837768 + ... + 3536920837773.

It is an arithmetic number, because the mean of its divisors is an integer number (7073841675542).

Almost surely, 2^{21221525026623} is an apocalyptic number.

21221525026623 is a deficient number, since it is larger than the sum of its proper divisors (7073841675545).

21221525026623 is an equidigital number, since it uses as much as digits as its factorization.

21221525026623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7073841675544.

The product of its (nonzero) digits is 172800, while the sum is 39.

Adding to 21221525026623 its reverse (32662052512212), we get a palindrome (53883577538835).

The spelling of 21221525026623 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred twenty-five million, twenty-six thousand, six hundred twenty-three".