1266606720 has 320 divisors, whose sum is σ = 4618623240. Its totient is φ = 330670080.

The previous prime is 1266606703. The next prime is 1266606739. The reversal of 1266606720 is 276066621.

It can be written as a sum of positive squares in 4 ways, for example, as 1035809856 + 230796864 = 32184^2 + 15192^2 .

It is a tau number, because it is divible by the number of its divisors (320).

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 39 ways as a sum of consecutive naturals, for example, 2747290 + ... + 2747750.

Almost surely, 2^1266606720 is an apocalyptic number.

1266606720 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 1266606720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2309311620).

1266606720 is an abundant number, since it is smaller than the sum of its proper divisors (3352016520).

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

1266606720 is an equidigital number, since it uses as much as digits as its factorization.

1266606720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 545 (or 524 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 1266606720 is about 35589.4186521781. The cubic root of 1266606720 is about 1081.9667864840.

The spelling of 1266606720 in words is "one billion, two hundred sixty-six million, six hundred six thousand, seven hundred twenty".