4378991 has 4 divisors (see below), whose sum is σ = 4480872. Its totient is φ = 4277112.

The previous prime is 4378981. The next prime is 4379003. The reversal of 4378991 is 1998734.

It is a happy number.

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 4378991 - 2¹⁴ = 4362607 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 (4378951) 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, 50876 + ... + 50961.

It is an arithmetic number, because the mean of its divisors is an integer number (1120218).

Almost surely, 2^4378991 is an apocalyptic number.

4378991 is a deficient number, since it is larger than the sum of its proper divisors (101881).

4378991 is a wasteful number, since it uses less digits than its factorization.

4378991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101880.

The product of its digits is 54432, while the sum is 41.

The square root of 4378991 is about 2092.6038803366. The cubic root of 4378991 is about 163.6030330637.

The spelling of 4378991 in words is "four million, three hundred seventy-eight thousand, nine hundred ninety-one".