1211728896 has 220 divisors, whose sum is σ = 4137363648. Its totient is φ = 346042368.

The previous prime is 1211728891. The next prime is 1211728913. The reversal of 1211728896 is 6988271121.

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is not an unprimeable number, because it can be changed into a prime (1211728891) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 579565 + ... + 581651.

Almost surely, 2^1211728896 is an apocalyptic number.

1211728896 is a gapful number since it is divisible by the number (16) 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 1211728896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2068681824).

1211728896 is an abundant number, since it is smaller than the sum of its proper divisors (2925634752).

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

1211728896 is an equidigital number, since it uses as much as digits as its factorization.

1211728896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2126 (or 2099 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The square root of 1211728896 is about 34809.8965238336. The cubic root of 1211728896 is about 1066.1095201503.

The spelling of 1211728896 in words is "one billion, two hundred eleven million, seven hundred twenty-eight thousand, eight hundred ninety-six".