3991389125 has 16 divisors (see below), whose sum is σ = 4987008000. Its totient is φ = 3189422800.

The previous prime is 3991389107. The next prime is 3991389197. The reversal of 3991389125 is 5219831993.

It is a happy number.

It is not a de Polignac number, because 3991389125 - 2¹⁸ = 3991126981 is a prime.

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, 92876 + ... + 128874.

It is an arithmetic number, because the mean of its divisors is an integer number (311688000).

Almost surely, 2^3991389125 is an apocalyptic number.

It is an amenable number.

3991389125 is a deficient number, since it is larger than the sum of its proper divisors (995618875).

3991389125 is an equidigital number, since it uses as much as digits as its factorization.

3991389125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36901 (or 36891 counting only the distinct ones).

The product of its digits is 524880, while the sum is 50.

The square root of 3991389125 is about 63177.4415832107. The cubic root of 3991389125 is about 1586.2611576164.

The spelling of 3991389125 in words is "three billion, nine hundred ninety-one million, three hundred eighty-nine thousand, one hundred twenty-five".