1266556320 has 72 divisors (see below), whose sum is σ = 4322128356. Its totient is φ = 337747968.

The previous prime is 1266556307. The next prime is 1266556337. The reversal of 1266556320 is 236556621.

It is a happy number.

1266556320 is a `hidden beast` number, since 12 + 6 + 6 + 5 + 5 + 632 + 0 = 666.

1266556320 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 1056770064 + 209786256 = 32508^2 + 14484^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 438337 + ... + 441216.

Almost surely, 2^1266556320 is an apocalyptic number.

1266556320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1266556320 is an abundant number, since it is smaller than the sum of its proper divisors (3055572036).

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

1266556320 is a wasteful number, since it uses less digits than its factorization.

1266556320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 879574 (or 879563 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The square root of 1266556320 is about 35588.7105695050. The cubic root of 1266556320 is about 1081.9524353182.

The spelling of 1266556320 in words is "one billion, two hundred sixty-six million, five hundred fifty-six thousand, three hundred twenty".