16721965562500 has 189 divisors, whose sum is σ = 40233541000177. Its totient is φ = 6076625500000.

The previous prime is 16721965562473. The next prime is 16721965562507. The reversal of 16721965562500 is 526556912761.

The square root of 16721965562500 is 4089250.

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

It can be written as a sum of positive squares in 3 ways, for example, as 14650047141444 + 2071918421056 = 3827538^2 + 1439416^2 .

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16721965562507) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 11245436757 + ... + 11245438243.

Almost surely, 2^{16721965562500} is an apocalyptic number.

16721965562500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16721965562500 is the 4089250-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16721965562500

16721965562500 is an abundant number, since it is smaller than the sum of its proper divisors (23511575437677).

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

16721965562500 is an frugal number, since it uses more digits than its factorization.

16721965562500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3030 (or 1505 counting only the distinct ones).

The product of its (nonzero) digits is 6804000, while the sum is 55.

The spelling of 16721965562500 in words is "sixteen trillion, seven hundred twenty-one billion, nine hundred sixty-five million, five hundred sixty-two thousand, five hundred".