31021340220 has 144 divisors (see below), whose sum is σ = 101897638752. Its totient is φ = 7593730560.

The previous prime is 31021340219. The next prime is 31021340243. The reversal of 31021340220 is 2204312013.

31021340220 is a `hidden beast` number, since 3 + 102 + 1 + 340 + 220 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31021340193 and 31021340202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 386919 + ... + 460161.

Almost surely, 2^31021340220 is an apocalyptic number.

31021340220 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31021340220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50948819376).

31021340220 is an abundant number, since it is smaller than the sum of its proper divisors (70876298532).

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

31021340220 is a wasteful number, since it uses less digits than its factorization.

31021340220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73452 (or 73447 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 31021340220 its reverse (2204312013), we get a palindrome (33225652233).

The spelling of 31021340220 in words is "thirty-one billion, twenty-one million, three hundred forty thousand, two hundred twenty".