31021012123 has 4 divisors (see below), whose sum is σ = 32845777560. Its totient is φ = 29196246688.

The previous prime is 31021012063. The next prime is 31021012129. The reversal of 31021012123 is 32121012013.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32121012013 = 31019 ⋅1035527.

It is a cyclic number.

It is not a de Polignac number, because 31021012123 - 2⁹ = 31021011611 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31021012097 and 31021012106.

It is not an unprimeable number, because it can be changed into a prime (31021012129) 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, 912382693 + ... + 912382726.

It is an arithmetic number, because the mean of its divisors is an integer number (8211444390).

Almost surely, 2^31021012123 is an apocalyptic number.

31021012123 is a deficient number, since it is larger than the sum of its proper divisors (1824765437).

31021012123 is a wasteful number, since it uses less digits than its factorization.

31021012123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1824765436.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 31021012123 its reverse (32121012013), we get a palindrome (63142024136).

The spelling of 31021012123 in words is "thirty-one billion, twenty-one million, twelve thousand, one hundred twenty-three".