31121231121 has 24 divisors (see below), whose sum is σ = 45205304040. Its totient is φ = 20631283200.

The previous prime is 31121231081. The next prime is 31121231131. The reversal of 31121231121 is 12113212113.

31121231121 is a `hidden beast` number, since 311 + 2 + 1 + 231 + 121 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 347300496 + 30773930625 = 18636^2 + 175425^2 .

It is not a de Polignac number, because 31121231121 - 2⁷ = 31121230993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31121231094 and 31121231103.

It is not an unprimeable number, because it can be changed into a prime (31121231131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1297881 + ... + 1321641.

It is an arithmetic number, because the mean of its divisors is an integer number (1883554335).

Almost surely, 2^31121231121 is an apocalyptic number.

It is an amenable number.

31121231121 is a deficient number, since it is larger than the sum of its proper divisors (14084072919).

31121231121 is a wasteful number, since it uses less digits than its factorization.

31121231121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24577 (or 24574 counting only the distinct ones).

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

Adding to 31121231121 its reverse (12113212113), we get a palindrome (43234443234).

The spelling of 31121231121 in words is "thirty-one billion, one hundred twenty-one million, two hundred thirty-one thousand, one hundred twenty-one".