3121992720 has 400 divisors, whose sum is σ = 13520884608. Its totient is φ = 648622080.

The previous prime is 3121992707. The next prime is 3121992779. The reversal of 3121992720 is 272991213.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 495832 + ... + 502088.

Almost surely, 2^3121992720 is an apocalyptic number.

3121992720 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 3121992720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6760442304).

3121992720 is an abundant number, since it is smaller than the sum of its proper divisors (10398891888).

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

3121992720 is a wasteful number, since it uses less digits than its factorization.

3121992720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6300 (or 6285 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 3121992720 is about 55874.7950331811. The cubic root of 3121992720 is about 1461.5397404520.

The spelling of 3121992720 in words is "three billion, one hundred twenty-one million, nine hundred ninety-two thousand, seven hundred twenty".