1266399 has 12 divisors (see below), whose sum is σ = 1879176. Its totient is φ = 821232.

The previous prime is 1266389. The next prime is 1266409. The reversal of 1266399 is 9936621.

1266399 is a `hidden beast` number, since 1 + 266 + 399 = 666.

It is an interprime number because it is at equal distance from previous prime (1266389) and next prime (1266409).

It is not a de Polignac number, because 1266399 - 2⁷ = 1266271 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266359) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 1569 + ... + 2234.

It is an arithmetic number, because the mean of its divisors is an integer number (156598).

2^1266399 is an apocalyptic number.

1266399 is a deficient number, since it is larger than the sum of its proper divisors (612777).

1266399 is a wasteful number, since it uses less digits than its factorization.

1266399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3846 (or 3843 counting only the distinct ones).

The product of its digits is 17496, while the sum is 36.

The square root of 1266399 is about 1125.3439474223. The cubic root of 1266399 is about 108.1907636730.

The spelling of 1266399 in words is "one million, two hundred sixty-six thousand, three hundred ninety-nine".