1266997255 has 4 divisors (see below), whose sum is σ = 1520396712. Its totient is φ = 1013597800.

The previous prime is 1266997243. The next prime is 1266997309. The reversal of 1266997255 is 5527996621.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1266997255 - 2⁵ = 1266997223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126699721 + ... + 126699730.

It is an arithmetic number, because the mean of its divisors is an integer number (380099178).

Almost surely, 2^1266997255 is an apocalyptic number.

1266997255 is a deficient number, since it is larger than the sum of its proper divisors (253399457).

1266997255 is an equidigital number, since it uses as much as digits as its factorization.

1266997255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253399456.

The product of its digits is 2041200, while the sum is 52.

The square root of 1266997255 is about 35594.9049022469. The cubic root of 1266997255 is about 1082.0779766090.

The spelling of 1266997255 in words is "one billion, two hundred sixty-six million, nine hundred ninety-seven thousand, two hundred fifty-five".