31021431123 has 4 divisors (see below), whose sum is σ = 41361908168. Its totient is φ = 20680954080.

The previous prime is 31021431121. The next prime is 31021431127. The reversal of 31021431123 is 32113412013.

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

It is not a de Polignac number, because 31021431123 - 2¹ = 31021431121 is a prime.

It is a super-2 number, since 2×31021431123² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31021431123.

It is not an unprimeable number, because it can be changed into a prime (31021431121) 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, 5170238518 + ... + 5170238523.

It is an arithmetic number, because the mean of its divisors is an integer number (10340477042).

Almost surely, 2^31021431123 is an apocalyptic number.

31021431123 is a deficient number, since it is larger than the sum of its proper divisors (10340477045).

31021431123 is a wasteful number, since it uses less digits than its factorization.

31021431123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10340477044.

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 31021431123 its reverse (32113412013), we get a palindrome (63134843136).

The spelling of 31021431123 in words is "thirty-one billion, twenty-one million, four hundred thirty-one thousand, one hundred twenty-three".