2556739 has 2 divisors, whose sum is σ = 2556740. Its totient is φ = 2556738.

The previous prime is 2556713. The next prime is 2556761. The reversal of 2556739 is 9376552.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2556739 - 2¹³ = 2548547 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2556698 and 2556707.

It is not a weakly prime, because it can be changed into another prime (2556139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1278369 + 1278370.

It is an arithmetic number, because the mean of its divisors is an integer number (1278370).

2^2556739 is an apocalyptic number.

2556739 is a deficient number, since it is larger than the sum of its proper divisors (1).

2556739 is an equidigital number, since it uses as much as digits as its factorization.

2556739 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56700, while the sum is 37.

The square root of 2556739 is about 1598.9806127655. The cubic root of 2556739 is about 136.7399653075.

The spelling of 2556739 in words is "two million, five hundred fifty-six thousand, seven hundred thirty-nine".