123131021231 has 4 divisors (see below), whose sum is σ = 123151249200. Its totient is φ = 123110793264.

The previous prime is 123131021183. The next prime is 123131021263. The reversal of 123131021231 is 132120131321.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123131021231 is a prime.

It is a super-2 number, since 2×123131021231² (a number of 23 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 (123131021291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10104851 + ... + 10117028.

It is an arithmetic number, because the mean of its divisors is an integer number (30787812300).

Almost surely, 2^123131021231 is an apocalyptic number.

123131021231 is a deficient number, since it is larger than the sum of its proper divisors (20227969).

123131021231 is an equidigital number, since it uses as much as digits as its factorization.

123131021231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20227968.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 123131021231 its reverse (132120131321), we get a palindrome (255251152552).

The spelling of 123131021231 in words is "one hundred twenty-three billion, one hundred thirty-one million, twenty-one thousand, two hundred thirty-one".