31143220 has 24 divisors (see below), whose sum is σ = 67511808. Its totient is φ = 12055200.

The previous prime is 31143199. The next prime is 31143239. The reversal of 31143220 is 2234113.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 31143194 and 31143203.

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, 24496 + ... + 25735.

It is an arithmetic number, because the mean of its divisors is an integer number (2812992).

Almost surely, 2^31143220 is an apocalyptic number.

It is an amenable number.

31143220 is an abundant number, since it is smaller than the sum of its proper divisors (36368588).

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

31143220 is a wasteful number, since it uses less digits than its factorization.

31143220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50271 (or 50269 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 31143220 is about 5580.6110776509. The cubic root of 31143220 is about 314.6210947561.

Adding to 31143220 its reverse (2234113), we get a palindrome (33377333).

The spelling of 31143220 in words is "thirty-one million, one hundred forty-three thousand, two hundred twenty".