2505857 has 2 divisors, whose sum is σ = 2505858.
Its totient is φ = 2505856.
The previous prime is 2505847. The next prime is 2505859. The reversal of 2505857 is 7585052.
It is a happy number.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 2202256 + 303601 = 1484^2 + 551^2
It is a cyclic number.
It is not a de Polignac number, because 2505857 - 26 = 2505793 is a prime.
Together with 2505859, it forms a pair of twin primes.
It is a Chen prime.
It is not a weakly prime, because it can be changed into another prime (2505859) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1252928 + 1252929.
It is an arithmetic number, because the mean of its divisors is an integer number (1252929).
22505857 is an apocalyptic number.
It is an amenable number.
2505857 is a deficient number, since it is larger than the sum of its proper divisors (1).
2505857 is an equidigital number, since it uses as much as digits as its factorization.
2505857 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 14000, while the sum is 32.
The square root of 2505857 is about 1582.9898925767.
The cubic root of 2505857 is about 135.8267871269.
Adding to 2505857 its sum of digits (32), we get a square (2505889 = 15832).
The spelling of 2505857 in words is "two million, five hundred five thousand, eight hundred fifty-seven".