1721616906816 has 189 divisors, whose sum is σ = 5160755848521. Its totient is φ = 548690402304.

The previous prime is 1721616906809. The next prime is 1721616906833. The reversal of 1721616906816 is 6186096161271.

The square root of 1721616906816 is 1312104.

It is a perfect power (a square), and thus also a powerful number.

1721616906816 is a `hidden beast` number, since 1 + 7 + 2 + 1 + 616 + 9 + 0 + 6 + 8 + 16 = 666.

It can be written as a sum of positive squares in only one way, i.e., 681021057600 + 1040595849216 = 825240^2 + 1020096^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 724280220 + ... + 724282596.

Almost surely, 2^{1721616906816} is an apocalyptic number.

1721616906816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1721616906816 is the 1312104-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1721616906816

1721616906816 is an abundant number, since it is smaller than the sum of its proper divisors (3439138941705).

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

1721616906816 is an frugal number, since it uses more digits than its factorization.

1721616906816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4818 (or 2405 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 1721616906816 in words is "one trillion, seven hundred twenty-one billion, six hundred sixteen million, nine hundred six thousand, eight hundred sixteen".