21000234231 has 24 divisors (see below), whose sum is σ = 31540279680. Its totient is φ = 13963155192.

The previous prime is 21000234163. The next prime is 21000234239. The reversal of 21000234231 is 13243200012.

It is not a de Polignac number, because 21000234231 - 2⁷ = 21000234103 is a prime.

It is a super-2 number, since 2×21000234231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000234239) 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, 21915 + ... + 206108.

It is an arithmetic number, because the mean of its divisors is an integer number (1314178320).

Almost surely, 2^21000234231 is an apocalyptic number.

21000234231 is a deficient number, since it is larger than the sum of its proper divisors (10540045449).

21000234231 is an equidigital number, since it uses as much as digits as its factorization.

21000234231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228417 (or 228405 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21000234231 its reverse (13243200012), we get a palindrome (34243434243).

The spelling of 21000234231 in words is "twenty-one billion, two hundred thirty-four thousand, two hundred thirty-one".