31124021111 has 4 divisors (see below), whose sum is σ = 32128021824. Its totient is φ = 30120020400.

The previous prime is 31124021041. The next prime is 31124021113. The reversal of 31124021111 is 11112042113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11112042113 = 2063 ⋅5386351.

It is a cyclic number.

It is not a de Polignac number, because 31124021111 - 2²² = 31119826807 is a prime.

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 31124021111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31124021113) 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, 502000310 + ... + 502000371.

It is an arithmetic number, because the mean of its divisors is an integer number (8032005456).

Almost surely, 2^31124021111 is an apocalyptic number.

31124021111 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

31124021111 is a deficient number, since it is larger than the sum of its proper divisors (1004000713).

31124021111 is a wasteful number, since it uses less digits than its factorization.

31124021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1004000712.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 31124021111 its reverse (11112042113), we get a palindrome (42236063224).

The spelling of 31124021111 in words is "thirty-one billion, one hundred twenty-four million, twenty-one thousand, one hundred eleven".