1266395880 has 64 divisors (see below), whose sum is σ = 3921753600. Its totient is φ = 326810880.

The previous prime is 1266395869. The next prime is 1266395887. The reversal of 1266395880 is 885936621.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1266395887) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166495 + ... + 173934.

It is an arithmetic number, because the mean of its divisors is an integer number (61277400).

Almost surely, 2^1266395880 is an apocalyptic number.

1266395880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1266395880 is an abundant number, since it is smaller than the sum of its proper divisors (2655357720).

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

1266395880 is a wasteful number, since it uses less digits than its factorization.

1266395880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340474 (or 340470 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 48.

The square root of 1266395880 is about 35586.4564125174. The cubic root of 1266395880 is about 1081.9067482384.

The spelling of 1266395880 in words is "one billion, two hundred sixty-six million, three hundred ninety-five thousand, eight hundred eighty".