1266820864 has 36 divisors (see below), whose sum is σ = 2638648656. Its totient is φ = 605868032.

The previous prime is 1266820847. The next prime is 1266820871. The reversal of 1266820864 is 4680286621.

It is a self number, because there is not a number n which added to its sum of digits gives 1266820864.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101689 + ... + 113464.

It is an arithmetic number, because the mean of its divisors is an integer number (73295796).

Almost surely, 2^1266820864 is an apocalyptic number.

It is an amenable number.

1266820864 is an abundant number, since it is smaller than the sum of its proper divisors (1371827792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1266820864 is an equidigital number, since it uses as much as digits as its factorization.

1266820864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215192 (or 215178 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 43.

The square root of 1266820864 is about 35592.4270596991. The cubic root of 1266820864 is about 1082.0277587484.

The spelling of 1266820864 in words is "one billion, two hundred sixty-six million, eight hundred twenty thousand, eight hundred sixty-four".