31111223121 has 16 divisors (see below), whose sum is σ = 50280765120. Its totient is φ = 18855286560.

The previous prime is 31111223107. The next prime is 31111223137. The reversal of 31111223121 is 12132211113.

31111223121 is a `hidden beast` number, since 311 + 11 + 223 + 121 = 666.

It is not a de Polignac number, because 31111223121 - 2¹¹ = 31111221073 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31111223094 and 31111223103.

It is not an unprimeable number, because it can be changed into a prime (31111223141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52375500 + ... + 52376093.

It is an arithmetic number, because the mean of its divisors is an integer number (3142547820).

Almost surely, 2^31111223121 is an apocalyptic number.

It is an amenable number.

31111223121 is a deficient number, since it is larger than the sum of its proper divisors (19169541999).

31111223121 is a wasteful number, since it uses less digits than its factorization.

31111223121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104751613 (or 104751607 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 31111223121 its reverse (12132211113), we get a palindrome (43243434234).

The spelling of 31111223121 in words is "thirty-one billion, one hundred eleven million, two hundred twenty-three thousand, one hundred twenty-one".