3181201920 has 720 divisors, whose sum is σ = 12850025760. Its totient is φ = 724598784.

The previous prime is 3181201897. The next prime is 3181201937. The reversal of 3181201920 is 291021813.

It is a tau number, because it is divible by the number of its divisors (720).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 73981419 + ... + 73981461.

It is an arithmetic number, because the mean of its divisors is an integer number (17847258).

Almost surely, 2^3181201920 is an apocalyptic number.

3181201920 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 3181201920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6425012880).

3181201920 is an abundant number, since it is smaller than the sum of its proper divisors (9668823840).

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

3181201920 is a wasteful number, since it uses less digits than its factorization.

3181201920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117 (or 85 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 3181201920 is about 56402.1446400755. The cubic root of 3181201920 is about 1470.7214007399.

The spelling of 3181201920 in words is "three billion, one hundred eighty-one million, two hundred one thousand, nine hundred twenty".