1721728816 has 40 divisors (see below), whose sum is σ = 3414495744. Its totient is φ = 840651840.

The previous prime is 1721728787. The next prime is 1721728837. The reversal of 1721728816 is 6188271271.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 366901 + ... + 371563.

Almost surely, 2^1721728816 is an apocalyptic number.

1721728816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1721728816 is a deficient number, since it is larger than the sum of its proper divisors (1692766928).

1721728816 is a wasteful number, since it uses less digits than its factorization.

1721728816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5209 (or 5203 counting only the distinct ones).

The product of its digits is 75264, while the sum is 43.

The square root of 1721728816 is about 41493.7201995675. The cubic root of 1721728816 is about 1198.5465773833.

The spelling of 1721728816 in words is "one billion, seven hundred twenty-one million, seven hundred twenty-eight thousand, eight hundred sixteen".