3131232221 has 16 divisors (see below), whose sum is σ = 3484024320. Its totient is φ = 2794599360.

The previous prime is 3131232217. The next prime is 3131232253. The reversal of 3131232221 is 1222321313.

It is a cyclic number.

It is not a de Polignac number, because 3131232221 - 2² = 3131232217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3131232193 and 3131232202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3131232211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 550490 + ... + 556148.

It is an arithmetic number, because the mean of its divisors is an integer number (217751520).

Almost surely, 2^3131232221 is an apocalyptic number.

3131232221 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

3131232221 is a deficient number, since it is larger than the sum of its proper divisors (352792099).

3131232221 is a wasteful number, since it uses less digits than its factorization.

3131232221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7076.

The product of its digits is 432, while the sum is 20.

The square root of 3131232221 is about 55957.4143523448. The cubic root of 3131232221 is about 1462.9801237179.

Adding to 3131232221 its reverse (1222321313), we get a palindrome (4353553534).

The spelling of 3131232221 in words is "three billion, one hundred thirty-one million, two hundred thirty-two thousand, two hundred twenty-one".