3181381820 has 48 divisors (see below), whose sum is σ = 6909143808. Its totient is φ = 1229230080.

The previous prime is 3181381817. The next prime is 3181381823. The reversal of 3181381820 is 281831813.

It is an interprime number because it is at equal distance from previous prime (3181381817) and next prime (3181381823).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3181381823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 353294 + ... + 362186.

It is an arithmetic number, because the mean of its divisors is an integer number (143940496).

Almost surely, 2^3181381820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3181381820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3454571904).

3181381820 is an abundant number, since it is smaller than the sum of its proper divisors (3727761988).

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

3181381820 is a wasteful number, since it uses less digits than its factorization.

3181381820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9510 (or 9508 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 3181381820 is about 56403.7394150423. The cubic root of 3181381820 is about 1470.7491237829.

The spelling of 3181381820 in words is "three billion, one hundred eighty-one million, three hundred eighty-one thousand, eight hundred twenty".