2778257 has 2 divisors, whose sum is σ = 2778258. Its totient is φ = 2778256.

The previous prime is 2778241. The next prime is 2778263. The reversal of 2778257 is 7528772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2676496 + 101761 = 1636^2 + 319^2 .

It is a cyclic number.

It is not a de Polignac number, because 2778257 - 2⁴ = 2778241 is a prime.

It is a super-3 number, since 3×2778257³ = 64333696585300021779, which contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2778257.

It is not a weakly prime, because it can be changed into another prime (2778227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1389128 + 1389129.

It is an arithmetic number, because the mean of its divisors is an integer number (1389129).

2^2778257 is an apocalyptic number.

It is an amenable number.

2778257 is a deficient number, since it is larger than the sum of its proper divisors (1).

2778257 is an equidigital number, since it uses as much as digits as its factorization.

2778257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54880, while the sum is 38.

The square root of 2778257 is about 1666.8104271332. The cubic root of 2778257 is about 140.5801942523.

The spelling of 2778257 in words is "two million, seven hundred seventy-eight thousand, two hundred fifty-seven".