3121297920 has 480 divisors, whose sum is σ = 12346366032. Its totient is φ = 721944576.

The previous prime is 3121297919. The next prime is 3121297967. The reversal of 3121297920 is 297921213.

It can be written as a sum of positive squares in 8 ways, for example, as 277422336 + 2843875584 = 16656^2 + 53328^2 .

It is a tau number, because it is divible by the number of its divisors (480).

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

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, 5091534 + ... + 5092146.

Almost surely, 2^3121297920 is an apocalyptic number.

3121297920 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 3121297920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6173183016).

3121297920 is an abundant number, since it is smaller than the sum of its proper divisors (9225068112).

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

3121297920 is a wasteful number, since it uses less digits than its factorization.

3121297920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672 (or 653 counting only the distinct ones).

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

The square root of 3121297920 is about 55868.5772147457. The cubic root of 3121297920 is about 1461.4313104370.

The spelling of 3121297920 in words is "three billion, one hundred twenty-one million, two hundred ninety-seven thousand, nine hundred twenty".