31221223232 has 14 divisors (see below), whose sum is σ = 61954614978. Its totient is φ = 15610611584.

The previous prime is 31221223219. The next prime is 31221223249. The reversal of 31221223232 is 23232212213.

It can be written as a sum of positive squares in only one way, i.e., 25900396096 + 5320827136 = 160936^2 + 72944^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31221223198 and 31221223207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 243915743 + ... + 243915870.

Almost surely, 2^31221223232 is an apocalyptic number.

31221223232 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

31221223232 is a deficient number, since it is larger than the sum of its proper divisors (30733391746).

31221223232 is an equidigital number, since it uses as much as digits as its factorization.

31221223232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487831625 (or 487831615 counting only the distinct ones).

The product of its digits is 1728, while the sum is 23.

Adding to 31221223232 its reverse (23232212213), we get a palindrome (54453435445).

The spelling of 31221223232 in words is "thirty-one billion, two hundred twenty-one million, two hundred twenty-three thousand, two hundred thirty-two".