21255333423 has 8 divisors (see below), whose sum is σ = 28728670128. Its totient is φ = 13976109504.

The previous prime is 21255333409. The next prime is 21255333443. The reversal of 21255333423 is 32433355212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21255333423 - 2⁵ = 21255333391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255333443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48527940 + ... + 48528377.

It is an arithmetic number, because the mean of its divisors is an integer number (3591083766).

Almost surely, 2^21255333423 is an apocalyptic number.

21255333423 is a deficient number, since it is larger than the sum of its proper divisors (7473336705).

21255333423 is an equidigital number, since it uses as much as digits as its factorization.

21255333423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97056393.

The product of its digits is 64800, while the sum is 33.

Adding to 21255333423 its reverse (32433355212), we get a palindrome (53688688635).

The spelling of 21255333423 in words is "twenty-one billion, two hundred fifty-five million, three hundred thirty-three thousand, four hundred twenty-three".