21255231030501 has 16 divisors (see below), whose sum is σ = 31847302682496. Its totient is φ = 12511440338496.

The previous prime is 21255231030487. The next prime is 21255231030511. The reversal of 21255231030501 is 10503013255212.

It is not a de Polignac number, because 21255231030501 - 2²⁵ = 21255197476069 is a prime.

It is a super-2 number, since 2×21255231030501² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255231030511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11847953970 + ... + 11847955763.

It is an arithmetic number, because the mean of its divisors is an integer number (1990456417656).

Almost surely, 2^{21255231030501} is an apocalyptic number.

It is an amenable number.

21255231030501 is a deficient number, since it is larger than the sum of its proper divisors (10592071651995).

21255231030501 is a wasteful number, since it uses less digits than its factorization.

21255231030501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23695909772.

The product of its (nonzero) digits is 9000, while the sum is 30.

Adding to 21255231030501 its reverse (10503013255212), we get a palindrome (31758244285713).

The spelling of 21255231030501 in words is "twenty-one trillion, two hundred fifty-five billion, two hundred thirty-one million, thirty thousand, five hundred one".