1255078811809 has 3 divisors (see below), whose sum is σ = 1255079932113. Its totient is φ = 1255077691506.

The previous prime is 1255078811759. The next prime is 1255078811813. The reversal of 1255078811809 is 9081188705521.

It is a happy number.

The square root of 1255078811809 is 1120303.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 1255078811809 - 2²⁵ = 1255045257377 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1255078811809.

It is not an unprimeable number, because it can be changed into a prime (1255078811879) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 560152 + ... + 1680454.

It is an arithmetic number, because the mean of its divisors is an integer number (418359977371).

Almost surely, 2^{1255078811809} is an apocalyptic number.

1255078811809 is the 1120303-rd square number.

1255078811809 is the 560152-nd centered octagonal number.

It is an amenable number.

1255078811809 is a deficient number, since it is larger than the sum of its proper divisors (1120304).

1255078811809 is an frugal number, since it uses more digits than its factorization.

1255078811809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2240606 (or 1120303 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 55.

The spelling of 1255078811809 in words is "one trillion, two hundred fifty-five billion, seventy-eight million, eight hundred eleven thousand, eight hundred nine".