1266988780 has 96 divisors (see below), whose sum is σ = 2909188800. Its totient is φ = 461832192.

The previous prime is 1266988771. The next prime is 1266988813. The reversal of 1266988780 is 878896621.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1363356 + ... + 1364284.

It is an arithmetic number, because the mean of its divisors is an integer number (30304050).

Almost surely, 2^1266988780 is an apocalyptic number.

1266988780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1266988780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1454594400).

1266988780 is an abundant number, since it is smaller than the sum of its proper divisors (1642200020).

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

1266988780 is a wasteful number, since it uses less digits than its factorization.

1266988780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1091 (or 1089 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 55.

The square root of 1266988780 is about 35594.7858541107. The cubic root of 1266988780 is about 1082.0755639146.

The spelling of 1266988780 in words is "one billion, two hundred sixty-six million, nine hundred eighty-eight thousand, seven hundred eighty".