3989521 has 4 divisors (see below), whose sum is σ = 4057200. Its totient is φ = 3921844.

The previous prime is 3989519. The next prime is 3989533. The reversal of 3989521 is 1259893.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1259893 = 709 ⋅1777.

It is a cyclic number.

It is not a de Polignac number, because 3989521 - 2¹ = 3989519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3989021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33751 + ... + 33868.

It is an arithmetic number, because the mean of its divisors is an integer number (1014300).

Almost surely, 2^3989521 is an apocalyptic number.

It is an amenable number.

3989521 is a deficient number, since it is larger than the sum of its proper divisors (67679).

3989521 is an equidigital number, since it uses as much as digits as its factorization.

3989521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67678.

The product of its digits is 19440, while the sum is 37.

The square root of 3989521 is about 1997.3785319764. The cubic root of 3989521 is about 158.6013641737.

The spelling of 3989521 in words is "three million, nine hundred eighty-nine thousand, five hundred twenty-one".