1721224893728 has 18 divisors (see below), whose sum is σ = 3388676120739. Its totient is φ = 860608736096.

The previous prime is 1721224893721. The next prime is 1721224893769. The reversal of 1721224893728 is 8273984221271.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 860612446864 + 860612446864 = 927692^2 + 927692^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=927692.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1721224893721) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7305575 + ... + 7537497.

Almost surely, 2^{1721224893728} is an apocalyptic number.

It is an amenable number.

1721224893728 is a deficient number, since it is larger than the sum of its proper divisors (1667451227011).

1721224893728 is an frugal number, since it uses more digits than its factorization.

1721224893728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463856 (or 231925 counting only the distinct ones).

The product of its digits is 5419008, while the sum is 56.

The spelling of 1721224893728 in words is "one trillion, seven hundred twenty-one billion, two hundred twenty-four million, eight hundred ninety-three thousand, seven hundred twenty-eight".