2278809 has 12 divisors (see below), whose sum is σ = 3544996. Its totient is φ = 1402272.

The previous prime is 2278807. The next prime is 2278811. The reversal of 2278809 is 9088722.

It is an interprime number because it is at equal distance from previous prime (2278807) and next prime (2278811).

It can be written as a sum of positive squares in 2 ways, for example, as 944784 + 1334025 = 972^2 + 1155^2 .

It is not a de Polignac number, because 2278809 - 2¹ = 2278807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2278807) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9622 + ... + 9855.

2^2278809 is an apocalyptic number.

It is an amenable number.

2278809 is a deficient number, since it is larger than the sum of its proper divisors (1266187).

2278809 is a wasteful number, since it uses less digits than its factorization.

2278809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19496 (or 19493 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 2278809 is about 1509.5724560285. The cubic root of 2278809 is about 131.5939658113.

The spelling of 2278809 in words is "two million, two hundred seventy-eight thousand, eight hundred nine".