31021222221 has 48 divisors (see below), whose sum is σ = 49956192000. Its totient is φ = 18391950720.

The previous prime is 31021222109. The next prime is 31021222231. The reversal of 31021222221 is 12222212013.

It is not a de Polignac number, because 31021222221 - 2¹⁷ = 31021091149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31021222194 and 31021222203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31021222231) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 834295 + ... + 870683.

It is an arithmetic number, because the mean of its divisors is an integer number (1040754000).

Almost surely, 2^31021222221 is an apocalyptic number.

It is an amenable number.

31021222221 is a deficient number, since it is larger than the sum of its proper divisors (18934969779).

31021222221 is a wasteful number, since it uses less digits than its factorization.

31021222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36594 (or 36591 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 31021222221 its reverse (12222212013), we get a palindrome (43243434234).

The spelling of 31021222221 in words is "thirty-one billion, twenty-one million, two hundred twenty-two thousand, two hundred twenty-one".