1255999 has 4 divisors (see below), whose sum is σ = 1260064. Its totient is φ = 1251936.

The previous prime is 1255997. The next prime is 1256009. The reversal of 1255999 is 9995521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9995521 = 61 ⋅163861.

It is a cyclic number.

It is not a de Polignac number, because 1255999 - 2¹ = 1255997 is a prime.

It is an Ulam number.

It is a Duffinian number.

1255999 is a lucky number.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1255993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1527 + ... + 2200.

It is an arithmetic number, because the mean of its divisors is an integer number (315016).

2^1255999 is an apocalyptic number.

1255999 is a deficient number, since it is larger than the sum of its proper divisors (4065).

1255999 is an equidigital number, since it uses as much as digits as its factorization.

1255999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4064.

The product of its digits is 36450, while the sum is 40.

The square root of 1255999 is about 1120.7136119455. The cubic root of 1255999 is about 107.8937856079.

The spelling of 1255999 in words is "one million, two hundred fifty-five thousand, nine hundred ninety-nine".