2778281 has 6 divisors (see below), whose sum is σ = 3053946. Its totient is φ = 2525600.

The previous prime is 2778277. The next prime is 2778299. The reversal of 2778281 is 1828772.

It can be written as a sum of positive squares in only one way, i.e., 2544025 + 234256 = 1595^2 + 484^2 .

It is not a de Polignac number, because 2778281 - 2² = 2778277 is a prime.

It is a super-2 number, since 2×2778281² = 15437690629922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2778241) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11360 + ... + 11601.

It is an arithmetic number, because the mean of its divisors is an integer number (508991).

2^2778281 is an apocalyptic number.

It is an amenable number.

2778281 is a deficient number, since it is larger than the sum of its proper divisors (275665).

2778281 is a wasteful number, since it uses less digits than its factorization.

2778281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22983 (or 22972 counting only the distinct ones).

The product of its digits is 12544, while the sum is 35.

The square root of 2778281 is about 1666.8176264967. The cubic root of 2778281 is about 140.5805990523.

It can be divided in two parts, 277 and 8281, that added together give a palindrome (8558).

The spelling of 2778281 in words is "two million, seven hundred seventy-eight thousand, two hundred eighty-one".