21123214231 has 8 divisors (see below), whose sum is σ = 24431670144. Its totient is φ = 17887471800.

The previous prime is 21123214201. The next prime is 21123214249. The reversal of 21123214231 is 13241232112.

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

It is a cyclic number.

It is not a de Polignac number, because 21123214231 - 2⁵ = 21123214199 is a prime.

It is a super-2 number, since 2×21123214231² (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 (21123214201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18177745 + ... + 18178906.

It is an arithmetic number, because the mean of its divisors is an integer number (3053958768).

Almost surely, 2^21123214231 is an apocalyptic number.

21123214231 is a deficient number, since it is larger than the sum of its proper divisors (3308455913).

21123214231 is an equidigital number, since it uses as much as digits as its factorization.

21123214231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36356741.

The product of its digits is 576, while the sum is 22.

Adding to 21123214231 its reverse (13241232112), we get a palindrome (34364446343).

The spelling of 21123214231 in words is "twenty-one billion, one hundred twenty-three million, two hundred fourteen thousand, two hundred thirty-one".