31220222221 has 8 divisors (see below), whose sum is σ = 31655382264. Its totient is φ = 30785264640.

The previous prime is 31220222177. The next prime is 31220222239. The reversal of 31220222221 is 12222202213.

It can be written as a sum of positive squares in 4 ways, for example, as 21735604900 + 9484617321 = 147430^2 + 97389^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 31220222221 - 2⁷ = 31220222093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31220222291) 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, 274365 + ... + 371101.

It is an arithmetic number, because the mean of its divisors is an integer number (3956922783).

Almost surely, 2^31220222221 is an apocalyptic number.

It is an amenable number.

31220222221 is a deficient number, since it is larger than the sum of its proper divisors (435160043).

31220222221 is an equidigital number, since it uses as much as digits as its factorization.

31220222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101231.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 31220222221 its reverse (12222202213), we get a palindrome (43442424434).

The spelling of 31220222221 in words is "thirty-one billion, two hundred twenty million, two hundred twenty-two thousand, two hundred twenty-one".