31222320221 has 4 divisors (see below), whose sum is σ = 31223883744. Its totient is φ = 31220756700.

The previous prime is 31222320211. The next prime is 31222320281. The reversal of 31222320221 is 12202322213.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12202322213 = 7057 ⋅1729109.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31222320221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31222320193 and 31222320202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31222320211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 751415 + ... + 791876.

It is an arithmetic number, because the mean of its divisors is an integer number (7805970936).

Almost surely, 2^31222320221 is an apocalyptic number.

It is an amenable number.

31222320221 is a deficient number, since it is larger than the sum of its proper divisors (1563523).

31222320221 is a wasteful number, since it uses less digits than its factorization.

31222320221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1563522.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 31222320221 its reverse (12202322213), we get a palindrome (43424642434).

The spelling of 31222320221 in words is "thirty-one billion, two hundred twenty-two million, three hundred twenty thousand, two hundred twenty-one".