1721986663680 has 576 divisors, whose sum is σ = 6178701312000. Its totient is φ = 454114418688.

The previous prime is 1721986663679. The next prime is 1721986663723. The reversal of 1721986663680 is 863666891271.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-2 number, since 2×1721986663680² (a number of 25 digits) 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 (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1346353281 + ... + 1346354559.

It is an arithmetic number, because the mean of its divisors is an integer number (10726912000).

Almost surely, 2^{1721986663680} is an apocalyptic number.

1721986663680 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 1721986663680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3089350656000).

1721986663680 is an abundant number, since it is smaller than the sum of its proper divisors (4456714648320).

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

1721986663680 is a wasteful number, since it uses less digits than its factorization.

1721986663680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1711 (or 1691 counting only the distinct ones).

The product of its (nonzero) digits is 31352832, while the sum is 63.

The spelling of 1721986663680 in words is "one trillion, seven hundred twenty-one billion, nine hundred eighty-six million, six hundred sixty-three thousand, six hundred eighty".