31231223320 has 32 divisors (see below), whose sum is σ = 76658458320. Its totient is φ = 11356808320.

The previous prime is 31231223293. The next prime is 31231223323. The reversal of 31231223320 is 2332213213.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 31231223291 and 31231223300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31231223323) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35489587 + ... + 35490466.

Almost surely, 2^31231223320 is an apocalyptic number.

It is an amenable number.

31231223320 is an abundant number, since it is smaller than the sum of its proper divisors (45427235000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31231223320 is a wasteful number, since it uses less digits than its factorization.

31231223320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70980075 (or 70980071 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 22.

Adding to 31231223320 its reverse (2332213213), we get a palindrome (33563436533).

The spelling of 31231223320 in words is "thirty-one billion, two hundred thirty-one million, two hundred twenty-three thousand, three hundred twenty".