3928891 has 4 divisors (see below), whose sum is σ = 4064400. Its totient is φ = 3793384.

The previous prime is 3928849. The next prime is 3928913. The reversal of 3928891 is 1988293.

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

It is a cyclic number.

It is not a de Polignac number, because 3928891 - 2¹⁷ = 3797819 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3928811) 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, 67711 + ... + 67768.

It is an arithmetic number, because the mean of its divisors is an integer number (1016100).

Almost surely, 2^3928891 is an apocalyptic number.

3928891 is the 1060-th centered heptagonal number.

3928891 is a deficient number, since it is larger than the sum of its proper divisors (135509).

3928891 is a wasteful number, since it uses less digits than its factorization.

3928891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135508.

The product of its digits is 31104, while the sum is 40.

The square root of 3928891 is about 1982.1430321750. The cubic root of 3928891 is about 157.7938212249.

The spelling of 3928891 in words is "three million, nine hundred twenty-eight thousand, eight hundred ninety-one".