1721530402172 has 12 divisors (see below), whose sum is σ = 3443060804400. Its totient is φ = 737798743776.

The previous prime is 1721530402133. The next prime is 1721530402231. The reversal of 1721530402172 is 2712040351271.

1721530402172 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30741614297 + ... + 30741614352.

It is an arithmetic number, because the mean of its divisors is an integer number (286921733700).

Almost surely, 2^{1721530402172} is an apocalyptic number.

It is an amenable number.

1721530402172 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1721530402172 is a wasteful number, since it uses less digits than its factorization.

1721530402172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61483228660 (or 61483228658 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 35.

The spelling of 1721530402172 in words is "one trillion, seven hundred twenty-one billion, five hundred thirty million, four hundred two thousand, one hundred seventy-two".