2578381 has 4 divisors (see below), whose sum is σ = 2776732. Its totient is φ = 2380032.

The previous prime is 2578351. The next prime is 2578391. The reversal of 2578381 is 1838752.

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

It can be written as a sum of positive squares in 2 ways, for example, as 864900 + 1713481 = 930^2 + 1309^2 .

It is a cyclic number.

It is not a de Polignac number, because 2578381 - 2⁵ = 2578349 is a prime.

It is a super-2 number, since 2×2578381² = 13296097162322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2578351) 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, 99156 + ... + 99181.

It is an arithmetic number, because the mean of its divisors is an integer number (694183).

2^2578381 is an apocalyptic number.

It is an amenable number.

2578381 is a deficient number, since it is larger than the sum of its proper divisors (198351).

2578381 is a wasteful number, since it uses less digits than its factorization.

2578381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198350.

The product of its digits is 13440, while the sum is 34.

The square root of 2578381 is about 1605.7337886462. The cubic root of 2578381 is about 137.1247021995.

The spelling of 2578381 in words is "two million, five hundred seventy-eight thousand, three hundred eighty-one".