3931581620 has 24 divisors (see below), whose sum is σ = 8541023400. Its totient is φ = 1518403712.

The previous prime is 3931581601. The next prime is 3931581623. The reversal of 3931581620 is 261851393.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1036711204 + 2894870416 = 32198^2 + 53804^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3931581623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3388715 + ... + 3389874.

It is an arithmetic number, because the mean of its divisors is an integer number (355875975).

Almost surely, 2^3931581620 is an apocalyptic number.

It is an amenable number.

3931581620 is an abundant number, since it is smaller than the sum of its proper divisors (4609441780).

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

3931581620 is a wasteful number, since it uses less digits than its factorization.

3931581620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6778627 (or 6778625 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 3931581620 is about 62702.3254752166. The cubic root of 3931581620 is about 1578.2983362042.

The spelling of 3931581620 in words is "three billion, nine hundred thirty-one million, five hundred eighty-one thousand, six hundred twenty".