31021980 has 72 divisors (see below), whose sum is σ = 95498256. Its totient is φ = 7518720.

The previous prime is 31021951. The next prime is 31021999. The reversal of 31021980 is 8912013.

It is a self number, because there is not a number n which added to its sum of digits gives 31021980.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5124 + ... + 9396.

Almost surely, 2^31021980 is an apocalyptic number.

31021980 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 31021980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47749128).

31021980 is an abundant number, since it is smaller than the sum of its proper divisors (64476276).

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

31021980 is a wasteful number, since it uses less digits than its factorization.

31021980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4307 (or 4294 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 31021980 is about 5569.7378753403. The cubic root of 31021980 is about 314.2122923727.

Adding to 31021980 its reverse (8912013), we get a palindrome (39933993).

The spelling of 31021980 in words is "thirty-one million, twenty-one thousand, nine hundred eighty".