2978391 has 8 divisors (see below), whose sum is σ = 4276720. Its totient is φ = 1832832.

The previous prime is 2978377. The next prime is 2978399. The reversal of 2978391 is 1938792.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2978391 - 2¹⁰ = 2977367 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 76369 = 2978391 / (2 + 9 + 7 + 8 + 3 + 9 + 1).

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a zygodrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2978399) 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 7 ways as a sum of consecutive naturals, for example, 38146 + ... + 38223.

It is an arithmetic number, because the mean of its divisors is an integer number (534590).

2^2978391 is an apocalyptic number.

2978391 is a deficient number, since it is larger than the sum of its proper divisors (1298329).

2978391 is a wasteful number, since it uses less digits than its factorization.

2978391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76385.

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

The square root of 2978391 is about 1725.8015529023. The cubic root of 2978391 is about 143.8778381376.

The spelling of 2978391 in words is "two million, nine hundred seventy-eight thousand, three hundred ninety-one".