31423203220 has 24 divisors (see below), whose sum is σ = 65992062024. Its totient is φ = 12568646016.

The previous prime is 31423203197. The next prime is 31423203241. The reversal of 31423203220 is 2230232413.

It can be written as a sum of positive squares in 4 ways, for example, as 3455323524 + 27967879696 = 58782^2 + 167236^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31423203191 and 31423203200.

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, 726934 + ... + 768946.

It is an arithmetic number, because the mean of its divisors is an integer number (2749669251).

Almost surely, 2^31423203220 is an apocalyptic number.

It is an amenable number.

31423203220 is an abundant number, since it is smaller than the sum of its proper divisors (34568858804).

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

31423203220 is a wasteful number, since it uses less digits than its factorization.

31423203220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79419 (or 79417 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 22.

Adding to 31423203220 its reverse (2230232413), we get a palindrome (33653435633).

The spelling of 31423203220 in words is "thirty-one billion, four hundred twenty-three million, two hundred three thousand, two hundred twenty".