3991985628 has 48 divisors (see below), whose sum is σ = 9886302720. Its totient is φ = 1249371904.

The previous prime is 3991985617. The next prime is 3991985651. The reversal of 3991985628 is 8265891993.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62125 + ... + 108827.

It is an arithmetic number, because the mean of its divisors is an integer number (205964640).

Almost surely, 2^3991985628 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 3991985628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4943151360).

3991985628 is an abundant number, since it is smaller than the sum of its proper divisors (5894317092).

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

3991985628 is a wasteful number, since it uses less digits than its factorization.

3991985628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47146 (or 47144 counting only the distinct ones).

The product of its digits is 8398080, while the sum is 60.

The square root of 3991985628 is about 63182.1622611952. The cubic root of 3991985628 is about 1586.3401745849.

The spelling of 3991985628 in words is "three billion, nine hundred ninety-one million, nine hundred eighty-five thousand, six hundred twenty-eight".