31121002221 has 8 divisors (see below), whose sum is σ = 41509004544. Its totient is φ = 20740167360.

The previous prime is 31121002181. The next prime is 31121002229. The reversal of 31121002221 is 12220012113.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31121002221 - 2¹⁷ = 31120871149 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31121002221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121002229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1781725 + ... + 1799106.

It is an arithmetic number, because the mean of its divisors is an integer number (5188625568).

Almost surely, 2^31121002221 is an apocalyptic number.

It is an amenable number.

31121002221 is a deficient number, since it is larger than the sum of its proper divisors (10388002323).

31121002221 is a wasteful number, since it uses less digits than its factorization.

31121002221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3583731.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 31121002221 its reverse (12220012113), we get a palindrome (43341014334).

The spelling of 31121002221 in words is "thirty-one billion, one hundred twenty-one million, two thousand, two hundred twenty-one".