31162221 has 6 divisors (see below), whose sum is σ = 45012110. Its totient is φ = 20774808.

The previous prime is 31162213. The next prime is 31162231. The reversal of 31162221 is 12226113.

It can be written as a sum of positive squares in only one way, i.e., 30140100 + 1022121 = 5490^2 + 1011^2 .

It is not a de Polignac number, because 31162221 - 2³ = 31162213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31162194 and 31162203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31162231) 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 5 ways as a sum of consecutive naturals, for example, 1731226 + ... + 1731243.

Almost surely, 2^31162221 is an apocalyptic number.

It is an amenable number.

31162221 is a deficient number, since it is larger than the sum of its proper divisors (13849889).

31162221 is a wasteful number, since it uses less digits than its factorization.

31162221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3462475 (or 3462472 counting only the distinct ones).

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

The square root of 31162221 is about 5582.3132301941. The cubic root of 31162221 is about 314.6850669471.

Adding to 31162221 its reverse (12226113), we get a palindrome (43388334).

The spelling of 31162221 in words is "thirty-one million, one hundred sixty-two thousand, two hundred twenty-one".