1266721896 has 96 divisors (see below), whose sum is σ = 3566102400. Its totient is φ = 374457600.

The previous prime is 1266721891. The next prime is 1266721909. The reversal of 1266721896 is 6981276621.

It is not an unprimeable number, because it can be changed into a prime (1266721891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 113745 + ... + 124383.

It is an arithmetic number, because the mean of its divisors is an integer number (37146900).

Almost surely, 2^1266721896 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 1266721896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1783051200).

1266721896 is an abundant number, since it is smaller than the sum of its proper divisors (2299380504).

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

1266721896 is a wasteful number, since it uses less digits than its factorization.

1266721896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10711 (or 10696 counting only the distinct ones).

The product of its digits is 435456, while the sum is 48.

The square root of 1266721896 is about 35591.0367367965. The cubic root of 1266721896 is about 1081.9995808860. Note that the first 3 decimals are identical.

The spelling of 1266721896 in words is "one billion, two hundred sixty-six million, seven hundred twenty-one thousand, eight hundred ninety-six".