31000032220 has 12 divisors (see below), whose sum is σ = 65100067704. Its totient is φ = 12400012880.

The previous prime is 31000032197. The next prime is 31000032221. The reversal of 31000032220 is 2223000013.

It is a happy number.

It is a super-2 number, since 2×31000032220² (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 31000032220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31000032221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 775000786 + ... + 775000825.

It is an arithmetic number, because the mean of its divisors is an integer number (5425005642).

Almost surely, 2^31000032220 is an apocalyptic number.

It is an amenable number.

31000032220 is an abundant number, since it is smaller than the sum of its proper divisors (34100035484).

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

31000032220 is a wasteful number, since it uses less digits than its factorization.

31000032220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1550001620 (or 1550001618 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 13.

Adding to 31000032220 its reverse (2223000013), we get a palindrome (33223032233).

The spelling of 31000032220 in words is "thirty-one billion, thirty-two thousand, two hundred twenty".