31001031220 has 24 divisors (see below), whose sum is σ = 65773326024. Its totient is φ = 12272572416.

The previous prime is 31001031211. The next prime is 31001031221. The reversal of 31001031220 is 2213010013.

It can be written as a sum of positive squares in 4 ways, for example, as 6104609424 + 24896421796 = 78132^2 + 157786^2 .

It is a super-2 number, since 2×31001031220² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31001031220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31001031221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7988017 + ... + 7991896.

It is an arithmetic number, because the mean of its divisors is an integer number (2740555251).

Almost surely, 2^31001031220 is an apocalyptic number.

It is an amenable number.

31001031220 is an abundant number, since it is smaller than the sum of its proper divisors (34772294804).

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

31001031220 is a wasteful number, since it uses less digits than its factorization.

31001031220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15980019 (or 15980017 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 31001031220 its reverse (2213010013), we get a palindrome (33214041233).

The spelling of 31001031220 in words is "thirty-one billion, one million, thirty-one thousand, two hundred twenty".