21004423255 has 12 divisors (see below), whose sum is σ = 25904952360. Its totient is φ = 16349383584.

The previous prime is 21004423243. The next prime is 21004423261. The reversal of 21004423255 is 55232440012.

It is not a de Polignac number, because 21004423255 - 2⁷ = 21004423127 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1527445 + ... + 1541134.

It is an arithmetic number, because the mean of its divisors is an integer number (2158746030).

Almost surely, 2^21004423255 is an apocalyptic number.

21004423255 is a deficient number, since it is larger than the sum of its proper divisors (4900529105).

21004423255 is an equidigital number, since it uses as much as digits as its factorization.

21004423255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3068658 (or 3068621 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 28.

Adding to 21004423255 its reverse (55232440012), we get a palindrome (76236863267).

The spelling of 21004423255 in words is "twenty-one billion, four million, four hundred twenty-three thousand, two hundred fifty-five".