31303220 has 24 divisors (see below), whose sum is σ = 70794024. Its totient is φ = 11558016.

The previous prime is 31303193. The next prime is 31303229. The reversal of 31303220 is 2230313.

It can be written as a sum of positive squares in 4 ways, for example, as 2808976 + 28494244 = 1676^2 + 5338^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31303195 and 31303204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31303229) 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, 59939 + ... + 60458.

It is an arithmetic number, because the mean of its divisors is an integer number (2949751).

Almost surely, 2^31303220 is an apocalyptic number.

It is an amenable number.

31303220 is an abundant number, since it is smaller than the sum of its proper divisors (39490804).

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

31303220 is a wasteful number, since it uses less digits than its factorization.

31303220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120419 (or 120417 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 14.

The square root of 31303220 is about 5594.9280603060. The cubic root of 31303220 is about 315.1589690593.

Adding to 31303220 its reverse (2230313), we get a palindrome (33533533).

The spelling of 31303220 in words is "thirty-one million, three hundred three thousand, two hundred twenty".