21323131231 has 8 divisors (see below), whose sum is σ = 21376750304. Its totient is φ = 21269576160.

The previous prime is 21323131199. The next prime is 21323131241. The reversal of 21323131231 is 13213132312.

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 21323131231 - 2⁵ = 21323131199 is a prime.

It is a super-2 number, since 2×21323131231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323131241) 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, 689701 + ... + 719953.

It is an arithmetic number, because the mean of its divisors is an integer number (2672093788).

Almost surely, 2^21323131231 is an apocalyptic number.

21323131231 is a deficient number, since it is larger than the sum of its proper divisors (53619073).

21323131231 is a wasteful number, since it uses less digits than its factorization.

21323131231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32001.

The product of its digits is 648, while the sum is 22.

Adding to 21323131231 its reverse (13213132312), we get a palindrome (34536263543).

The spelling of 21323131231 in words is "twenty-one billion, three hundred twenty-three million, one hundred thirty-one thousand, two hundred thirty-one".