3891729 has 4 divisors (see below), whose sum is σ = 5188976. Its totient is φ = 2594484.

The previous prime is 3891721. The next prime is 3891733. The reversal of 3891729 is 9271983.

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.

It is not a de Polignac number, because 3891729 - 2³ = 3891721 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (3891721) 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, 648619 + ... + 648624.

It is an arithmetic number, because the mean of its divisors is an integer number (1297244).

Almost surely, 2^3891729 is an apocalyptic number.

It is an amenable number.

3891729 is a deficient number, since it is larger than the sum of its proper divisors (1297247).

3891729 is a wasteful number, since it uses less digits than its factorization.

3891729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1297246.

The product of its digits is 27216, while the sum is 39.

The square root of 3891729 is about 1972.7465625366. The cubic root of 3891729 is about 157.2947389095.

The spelling of 3891729 in words is "three million, eight hundred ninety-one thousand, seven hundred twenty-nine".