1266638208 has 128 divisors (see below), whose sum is σ = 3689331840. Its totient is φ = 381849600.

The previous prime is 1266638179. The next prime is 1266638239. The reversal of 1266638208 is 8028366621.

It is a tau number, because it is divible by the number of its divisors (128).

It is a self number, because there is not a number n which added to its sum of digits gives 1266638208.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 958188 + ... + 959508.

It is an arithmetic number, because the mean of its divisors is an integer number (28822905).

Almost surely, 2^1266638208 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 1266638208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1844665920).

1266638208 is an abundant number, since it is smaller than the sum of its proper divisors (2422693632).

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

1266638208 is a wasteful number, since it uses less digits than its factorization.

1266638208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1576 (or 1564 counting only the distinct ones).

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

The square root of 1266638208 is about 35589.8610281074. The cubic root of 1266638208 is about 1081.9757523525.

The spelling of 1266638208 in words is "one billion, two hundred sixty-six million, six hundred thirty-eight thousand, two hundred eight".