31221133209 has 40 divisors (see below), whose sum is σ = 53327662080. Its totient is φ = 17831954304.

The previous prime is 31221133189. The next prime is 31221133211. The reversal of 31221133209 is 90233112213.

31221133209 is a `hidden beast` number, since 312 + 2 + 11 + 332 + 0 + 9 = 666.

It is not a de Polignac number, because 31221133209 - 2⁹ = 31221132697 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (31221133219) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1257217 + ... + 1281809.

It is an arithmetic number, because the mean of its divisors is an integer number (1333191552).

Almost surely, 2^31221133209 is an apocalyptic number.

It is an amenable number.

31221133209 is a deficient number, since it is larger than the sum of its proper divisors (22106528871).

31221133209 is a wasteful number, since it uses less digits than its factorization.

31221133209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26851 (or 26842 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The spelling of 31221133209 in words is "thirty-one billion, two hundred twenty-one million, one hundred thirty-three thousand, two hundred nine".