31121030020 has 36 divisors (see below), whose sum is σ = 66443265252. Its totient is φ = 12244310400.

The previous prime is 31121029987. The next prime is 31121030041. The reversal of 31121030020 is 2003012113.

It can be written as a sum of positive squares in 6 ways, for example, as 8279544064 + 22841485956 = 90992^2 + 151134^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 134671 + ... + 283510.

It is an arithmetic number, because the mean of its divisors is an integer number (1845646257).

Almost surely, 2^31121030020 is an apocalyptic number.

It is an amenable number.

31121030020 is an abundant number, since it is smaller than the sum of its proper divisors (35322235232).

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

31121030020 is a wasteful number, since it uses less digits than its factorization.

31121030020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418312 (or 418249 counting only the distinct ones).

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

Adding to 31121030020 its reverse (2003012113), we get a palindrome (33124042133).

The spelling of 31121030020 in words is "thirty-one billion, one hundred twenty-one million, thirty thousand, twenty".