31021113221 has 16 divisors (see below), whose sum is σ = 36051185280. Its totient is φ = 26144389440.

The previous prime is 31021113199. The next prime is 31021113247. The reversal of 31021113221 is 12231112013.

It is a cyclic number.

It is not a de Polignac number, because 31021113221 - 2¹⁴ = 31021096837 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 31021113221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31021113521) 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, 55226 + ... + 255131.

It is an arithmetic number, because the mean of its divisors is an integer number (2253199080).

Almost surely, 2^31021113221 is an apocalyptic number.

It is an amenable number.

31021113221 is a deficient number, since it is larger than the sum of its proper divisors (5030072059).

31021113221 is a wasteful number, since it uses less digits than its factorization.

31021113221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310604.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 31021113221 its reverse (12231112013), we get a palindrome (43252225234).

The spelling of 31021113221 in words is "thirty-one billion, twenty-one million, one hundred thirteen thousand, two hundred twenty-one".