1211728680 has 128 divisors (see below), whose sum is σ = 4047120000. Its totient is φ = 322486272.

The previous prime is 1211728673. The next prime is 1211728697. The reversal of 1211728680 is 868271121.

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

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 829791 + ... + 831249.

It is an arithmetic number, because the mean of its divisors is an integer number (31618125).

Almost surely, 2^1211728680 is an apocalyptic number.

1211728680 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 1211728680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2023560000).

1211728680 is an abundant number, since it is smaller than the sum of its proper divisors (2835391320).

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

1211728680 is a wasteful number, since it uses less digits than its factorization.

1211728680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2248 (or 2238 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 36.

The square root of 1211728680 is about 34809.8934212675. The cubic root of 1211728680 is about 1066.1094568029.

The spelling of 1211728680 in words is "one billion, two hundred eleven million, seven hundred twenty-eight thousand, six hundred eighty".