1219717728 has 144 divisors (see below), whose sum is σ = 3686089680. Its totient is φ = 381846528.

The previous prime is 1219717703. The next prime is 1219717769. The reversal of 1219717728 is 8277179121.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×1219717728² = 2975422671994963968, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 307051 + ... + 310997.

It is an arithmetic number, because the mean of its divisors is an integer number (25597845).

Almost surely, 2^1219717728 is an apocalyptic number.

1219717728 is a gapful number since it is divisible by the number (18) 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 1219717728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1843044840).

1219717728 is an abundant number, since it is smaller than the sum of its proper divisors (2466371952).

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

1219717728 is a wasteful number, since it uses less digits than its factorization.

1219717728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4029 (or 4018 counting only the distinct ones).

The product of its digits is 98784, while the sum is 45.

The square root of 1219717728 is about 34924.4574474680. The cubic root of 1219717728 is about 1068.4473150427.

The spelling of 1219717728 in words is "one billion, two hundred nineteen million, seven hundred seventeen thousand, seven hundred twenty-eight".