21223123031 has 24 divisors (see below), whose sum is σ = 23643258912. Its totient is φ = 19034312000.

The previous prime is 21223123021. The next prime is 21223123037. The reversal of 21223123031 is 13032132212.

It is a de Polignac number, because none of the positive numbers 2^k-21223123031 is a prime.

It is a super-2 number, since 2×21223123031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21223122994 and 21223123012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223123037) 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, 3577790 + ... + 3583716.

It is an arithmetic number, because the mean of its divisors is an integer number (985135788).

Almost surely, 2^21223123031 is an apocalyptic number.

21223123031 is a deficient number, since it is larger than the sum of its proper divisors (2420135881).

21223123031 is a wasteful number, since it uses less digits than its factorization.

21223123031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6343 (or 6332 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21223123031 its reverse (13032132212), we get a palindrome (34255255243).

The spelling of 21223123031 in words is "twenty-one billion, two hundred twenty-three million, one hundred twenty-three thousand, thirty-one".