1721221305564 has 48 divisors (see below), whose sum is σ = 4253712019200. Its totient is φ = 539828088576.

The previous prime is 1721221305563. The next prime is 1721221305641. The reversal of 1721221305564 is 4655031221271.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1721221305563) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 593994 + ... + 1948145.

It is an arithmetic number, because the mean of its divisors is an integer number (88619000400).

Almost surely, 2^{1721221305564} is an apocalyptic number.

It is an amenable number.

1721221305564 is an abundant number, since it is smaller than the sum of its proper divisors (2532490713636).

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

1721221305564 is a wasteful number, since it uses less digits than its factorization.

1721221305564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2545482 (or 2545480 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 39.

The spelling of 1721221305564 in words is "one trillion, seven hundred twenty-one billion, two hundred twenty-one million, three hundred five thousand, five hundred sixty-four".