3991828640 has 24 divisors (see below), whose sum is σ = 9430695540. Its totient is φ = 1596731392.

The previous prime is 3991828619. The next prime is 3991828651. The reversal of 3991828640 is 468281993.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 3959429776 + 32398864 = 62924^2 + 5692^2 .

It is a super-2 number, since 2×3991828640² = 31869391782248499200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12474305 + ... + 12474624.

Almost surely, 2^3991828640 is an apocalyptic number.

It is an amenable number.

3991828640 is an abundant number, since it is smaller than the sum of its proper divisors (5438866900).

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

3991828640 is a wasteful number, since it uses less digits than its factorization.

3991828640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24948944 (or 24948936 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 50.

The square root of 3991828640 is about 63180.9199046674. The cubic root of 3991828640 is about 1586.3193796173.

The spelling of 3991828640 in words is "three billion, nine hundred ninety-one million, eight hundred twenty-eight thousand, six hundred forty".