1255861 has 2 divisors, whose sum is σ = 1255862. Its totient is φ = 1255860.

The previous prime is 1255847. The next prime is 1255907. The reversal of 1255861 is 1685521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 792100 + 463761 = 890^2 + 681^2 .

It is an emirp because it is prime and its reverse (1685521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1255861 - 2⁵ = 1255829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1255801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 627930 + 627931.

It is an arithmetic number, because the mean of its divisors is an integer number (627931).

2^1255861 is an apocalyptic number.

It is an amenable number.

1255861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1255861 is an equidigital number, since it uses as much as digits as its factorization.

1255861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 28.

The square root of 1255861 is about 1120.6520423396. The cubic root of 1255861 is about 107.8898339361.

It can be divided in two parts, 1255 and 861, that added together give a square (2116 = 46²).

The spelling of 1255861 in words is "one million, two hundred fifty-five thousand, eight hundred sixty-one".