31203223220 has 24 divisors (see below), whose sum is σ = 70567290024. Its totient is φ = 11521190016.

The previous prime is 31203223213. The next prime is 31203223241. The reversal of 31203223220 is 2232230213.

It can be written as a sum of positive squares in 4 ways, for example, as 6363571984 + 24839651236 = 79772^2 + 157606^2 .

It is a super-2 number, since 2×31203223220² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 31203223192 and 31203223201.

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, 60005939 + ... + 60006458.

It is an arithmetic number, because the mean of its divisors is an integer number (2940303751).

Almost surely, 2^31203223220 is an apocalyptic number.

It is an amenable number.

31203223220 is an abundant number, since it is smaller than the sum of its proper divisors (39364066804).

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

31203223220 is a wasteful number, since it uses less digits than its factorization.

31203223220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120012419 (or 120012417 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 20.

Adding to 31203223220 its reverse (2232230213), we get a palindrome (33435453433).

The spelling of 31203223220 in words is "thirty-one billion, two hundred three million, two hundred twenty-three thousand, two hundred twenty".