31031021222221 has 8 divisors (see below), whose sum is σ = 31618848482424. Its totient is φ = 30443280491520.

The previous prime is 31031021222141. The next prime is 31031021222261. The reversal of 31031021222221 is 12222212013013.

It can be written as a sum of positive squares in 4 ways, for example, as 20083618175625 + 10947403046596 = 4481475^2 + 3308686^2 .

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 31031021222221 - 2³¹ = 31028873738573 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31031021222192 and 31031021222201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31031021222261) 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, 20908120 + ... + 22343041.

It is an arithmetic number, because the mean of its divisors is an integer number (3952356060303).

Almost surely, 2^{31031021222221} is an apocalyptic number.

It is an amenable number.

31031021222221 is a deficient number, since it is larger than the sum of its proper divisors (587827260203).

31031021222221 is a wasteful number, since it uses less digits than its factorization.

31031021222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43264751.

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 31031021222221 its reverse (12222212013013), we get a palindrome (43253233235234).

The spelling of 31031021222221 in words is "thirty-one trillion, thirty-one billion, twenty-one million, two hundred twenty-two thousand, two hundred twenty-one".