31323223220 has 24 divisors (see below), whose sum is σ = 65795176608. Its totient is φ = 12526164000.

The previous prime is 31323223213. The next prime is 31323223247. The reversal of 31323223220 is 2232232313.

It is a super-2 number, since 2×31323223220² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112286 + ... + 274325.

It is an arithmetic number, because the mean of its divisors is an integer number (2741465692).

Almost surely, 2^31323223220 is an apocalyptic number.

It is an amenable number.

31323223220 is an abundant number, since it is smaller than the sum of its proper divisors (34471953388).

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

31323223220 is a wasteful number, since it uses less digits than its factorization.

31323223220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390671 (or 390669 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 23.

Adding to 31323223220 its reverse (2232232313), we get a palindrome (33555455533).

The spelling of 31323223220 in words is "thirty-one billion, three hundred twenty-three million, two hundred twenty-three thousand, two hundred twenty".