31222161 has 12 divisors (see below), whose sum is σ = 45377488. Its totient is φ = 20686104.

The previous prime is 31222157. The next prime is 31222211. The reversal of 31222161 is 16122213.

It is not a de Polignac number, because 31222161 - 2² = 31222157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31222861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9175 + ... + 12108.

Almost surely, 2^31222161 is an apocalyptic number.

It is an amenable number.

31222161 is a deficient number, since it is larger than the sum of its proper divisors (14155327).

31222161 is a wasteful number, since it uses less digits than its factorization.

31222161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21452 (or 21449 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 31222161 is about 5587.6793930933. The cubic root of 31222161 is about 314.8867015064.

Adding to 31222161 its reverse (16122213), we get a palindrome (47344374).

The spelling of 31222161 in words is "thirty-one million, two hundred twenty-two thousand, one hundred sixty-one".