1266820863 has 48 divisors (see below), whose sum is σ = 2151196416. Its totient is φ = 655724160.

The previous prime is 1266820847. The next prime is 1266820871. The reversal of 1266820863 is 3680286621.

It is not a de Polignac number, because 1266820863 - 2⁴ = 1266820847 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266820823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 504870 + ... + 507372.

It is an arithmetic number, because the mean of its divisors is an integer number (44816592).

Almost surely, 2^1266820863 is an apocalyptic number.

1266820863 is a deficient number, since it is larger than the sum of its proper divisors (884375553).

1266820863 is a wasteful number, since it uses less digits than its factorization.

1266820863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2844 (or 2837 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 1266820863 is about 35592.4270456512. The cubic root of 1266820863 is about 1082.0277584637.

The spelling of 1266820863 in words is "one billion, two hundred sixty-six million, eight hundred twenty thousand, eight hundred sixty-three".