31221222129 has 12 divisors (see below), whose sum is σ = 45128898100. Its totient is φ = 20799573984.

The previous prime is 31221222127. The next prime is 31221222203. The reversal of 31221222129 is 92122212213.

31221222129 is a `hidden beast` number, since 312 + 2 + 1 + 222 + 129 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 19372464225 + 11848757904 = 139185^2 + 108852^2 .

It is not a de Polignac number, because 31221222129 - 2¹ = 31221222127 is a prime.

It is a super-2 number, since 2×31221222129² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31221222127) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1200934 + ... + 1226655.

Almost surely, 2^31221222129 is an apocalyptic number.

It is an amenable number.

31221222129 is a deficient number, since it is larger than the sum of its proper divisors (13907675971).

31221222129 is a wasteful number, since it uses less digits than its factorization.

31221222129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2429024 (or 2429021 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The spelling of 31221222129 in words is "thirty-one billion, two hundred twenty-one million, two hundred twenty-two thousand, one hundred twenty-nine".