3878991 has 6 divisors (see below), whose sum is σ = 5603000. Its totient is φ = 2585988.

The previous prime is 3878981. The next prime is 3878993. The reversal of 3878991 is 1998783.

It is not a de Polignac number, because 3878991 - 2¹⁵ = 3846223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3878993) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 215491 + ... + 215508.

Almost surely, 2^3878991 is an apocalyptic number.

3878991 is a deficient number, since it is larger than the sum of its proper divisors (1724009).

3878991 is a wasteful number, since it uses less digits than its factorization.

3878991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431005 (or 431002 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 3878991 is about 1969.5154226357. The cubic root of 3878991 is about 157.1229377742.

The spelling of 3878991 in words is "three million, eight hundred seventy-eight thousand, nine hundred ninety-one".