1266891888 has 80 divisors (see below), whose sum is σ = 3421495296. Its totient is φ = 403180800.

The previous prime is 1266891881. The next prime is 1266891907. The reversal of 1266891888 is 8881986621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266891881) 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, 1100113 + ... + 1101263.

Almost surely, 2^1266891888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1266891888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1710747648).

1266891888 is an abundant number, since it is smaller than the sum of its proper divisors (2154603408).

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

1266891888 is a wasteful number, since it uses less digits than its factorization.

1266891888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2182 (or 2176 counting only the distinct ones).

The product of its digits is 2654208, while the sum is 57.

The square root of 1266891888 is about 35593.4247860472. The cubic root of 1266891888 is about 1082.0479795772.

The spelling of 1266891888 in words is "one billion, two hundred sixty-six million, eight hundred ninety-one thousand, eight hundred eighty-eight".