3991429 has 4 divisors (see below), whose sum is σ = 4298476. Its totient is φ = 3684384.

The previous prime is 3991399. The next prime is 3991441. The reversal of 3991429 is 9241993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 362404 + 3629025 = 602^2 + 1905^2 .

It is a cyclic number.

It is not a de Polignac number, because 3991429 - 2¹⁷ = 3860357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 153504 + ... + 153529.

It is an arithmetic number, because the mean of its divisors is an integer number (1074619).

Almost surely, 2^3991429 is an apocalyptic number.

It is an amenable number.

3991429 is a deficient number, since it is larger than the sum of its proper divisors (307047).

3991429 is a wasteful number, since it uses less digits than its factorization.

3991429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307046.

The product of its digits is 17496, while the sum is 37.

The square root of 3991429 is about 1997.8561009242. The cubic root of 3991429 is about 158.6266439984.

The spelling of 3991429 in words is "three million, nine hundred ninety-one thousand, four hundred twenty-nine".