21444423255 has 24 divisors (see below), whose sum is σ = 37202385168. Its totient is φ = 11427163776.

The previous prime is 21444423251. The next prime is 21444423263. The reversal of 21444423255 is 55232444412.

It is not a de Polignac number, because 21444423255 - 2² = 21444423251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444423251) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 152542 + ... + 257211.

It is an arithmetic number, because the mean of its divisors is an integer number (1550099382).

Almost surely, 2^21444423255 is an apocalyptic number.

21444423255 is a deficient number, since it is larger than the sum of its proper divisors (15757961913).

21444423255 is a wasteful number, since it uses less digits than its factorization.

21444423255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410927 (or 410924 counting only the distinct ones).

The product of its digits is 153600, while the sum is 36.

Adding to 21444423255 its reverse (55232444412), we get a palindrome (76676867667).

The spelling of 21444423255 in words is "twenty-one billion, four hundred forty-four million, four hundred twenty-three thousand, two hundred fifty-five".