31220002121 has 24 divisors (see below), whose sum is σ = 41347978176. Its totient is φ = 22896241920.

The previous prime is 31220002111. The next prime is 31220002129. The reversal of 31220002121 is 12120002213.

It is a happy number.

It is not a de Polignac number, because 31220002121 - 2¹⁴ = 31219985737 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31220002096 and 31220002105.

It is not an unprimeable number, because it can be changed into a prime (31220002129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 679226 + ... + 723731.

It is an arithmetic number, because the mean of its divisors is an integer number (1722832424).

Almost surely, 2^31220002121 is an apocalyptic number.

It is an amenable number.

31220002121 is a deficient number, since it is larger than the sum of its proper divisors (10127976055).

31220002121 is a wasteful number, since it uses less digits than its factorization.

31220002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1403009 (or 1402992 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 31220002121 its reverse (12120002213), we get a palindrome (43340004334).

The spelling of 31220002121 in words is "thirty-one billion, two hundred twenty million, two thousand, one hundred twenty-one".