3989721825 has 30 divisors (see below), whose sum is σ = 7390347734. Its totient is φ = 2127850560.

The previous prime is 3989721817. The next prime is 3989721833. The reversal of 3989721825 is 5281279893.

3989721825 is a `hidden beast` number, since 398 + 9 + 72 + 182 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (3989721817) and next prime (3989721833).

It can be written as a sum of positive squares in 3 ways, for example, as 16184529 + 3973537296 = 4023^2 + 63036^2 .

It is not a de Polignac number, because 3989721825 - 2³ = 3989721817 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 983092 + ... + 987141.

Almost surely, 2^3989721825 is an apocalyptic number.

It is an amenable number.

3989721825 is a deficient number, since it is larger than the sum of its proper divisors (3400625909).

3989721825 is a wasteful number, since it uses less digits than its factorization.

3989721825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1970255 (or 1970241 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 54.

The square root of 3989721825 is about 63164.2448304419. The cubic root of 3989721825 is about 1586.0402536076.

The spelling of 3989721825 in words is "three billion, nine hundred eighty-nine million, seven hundred twenty-one thousand, eight hundred twenty-five".