3990749 has 4 divisors (see below), whose sum is σ = 4560864. Its totient is φ = 3420636.

The previous prime is 3990737. The next prime is 3990761. The reversal of 3990749 is 9470993.

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: 9470993 = 7 ⋅1352999.

It is an interprime number because it is at equal distance from previous prime (3990737) and next prime (3990761).

It is a cyclic number.

It is not a de Polignac number, because 3990749 - 2¹⁶ = 3925213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3990449) 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, 285047 + ... + 285060.

It is an arithmetic number, because the mean of its divisors is an integer number (1140216).

Almost surely, 2^3990749 is an apocalyptic number.

It is an amenable number.

3990749 is a deficient number, since it is larger than the sum of its proper divisors (570115).

3990749 is an equidigital number, since it uses as much as digits as its factorization.

3990749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570114.

The product of its (nonzero) digits is 61236, while the sum is 41.

The square root of 3990749 is about 1997.6859112483. The cubic root of 3990749 is about 158.6176353414.

The spelling of 3990749 in words is "three million, nine hundred ninety thousand, seven hundred forty-nine".