2815381 has 4 divisors (see below), whose sum is σ = 2818764. Its totient is φ = 2812000.

The previous prime is 2815369. The next prime is 2815399. The reversal of 2815381 is 1835182.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1835182 = 2 ⋅917591.

It can be written as a sum of positive squares in 2 ways, for example, as 654481 + 2160900 = 809^2 + 1470^2 .

It is a cyclic number.

It is not a de Polignac number, because 2815381 - 2¹¹ = 2813333 is a prime.

It is a super-2 number, since 2×2815381² = 15852740350322, 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 (2815301) 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 3 ways as a sum of consecutive naturals, for example, 531 + ... + 2431.

It is an arithmetic number, because the mean of its divisors is an integer number (704691).

2^2815381 is an apocalyptic number.

It is an amenable number.

2815381 is a deficient number, since it is larger than the sum of its proper divisors (3383).

2815381 is a wasteful number, since it uses less digits than its factorization.

2815381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3382.

The product of its digits is 1920, while the sum is 28.

The square root of 2815381 is about 1677.9097115161. The cubic root of 2815381 is about 141.2035856585.

The spelling of 2815381 in words is "two million, eight hundred fifteen thousand, three hundred eighty-one".