3990191285 has 4 divisors (see below), whose sum is σ = 4788229548. Its totient is φ = 3192153024.

The previous prime is 3990191221. The next prime is 3990191323. The reversal of 3990191285 is 5821910993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5821910993 = 54181 ⋅107453.

It can be written as a sum of positive squares in 2 ways, for example, as 3127829329 + 862361956 = 55927^2 + 29366^2 .

It is a cyclic number.

It is not a de Polignac number, because 3990191285 - 2⁶ = 3990191221 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 399019124 + ... + 399019133.

It is an arithmetic number, because the mean of its divisors is an integer number (1197057387).

Almost surely, 2^3990191285 is an apocalyptic number.

It is an amenable number.

3990191285 is a deficient number, since it is larger than the sum of its proper divisors (798038263).

3990191285 is an equidigital number, since it uses as much as digits as its factorization.

3990191285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798038262.

The product of its (nonzero) digits is 174960, while the sum is 47.

The square root of 3990191285 is about 63167.9609058263. The cubic root of 3990191285 is about 1586.1024595530.

The spelling of 3990191285 in words is "three billion, nine hundred ninety million, one hundred ninety-one thousand, two hundred eighty-five".