173838129721 has 9 divisors (see below), whose sum is σ = 174556126479. Its totient is φ = 173123079336.

The previous prime is 173838129713. The next prime is 173838129737. The reversal of 173838129721 is 127921838371.

The square root of 173838129721 is 416939.

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

It can be written as a sum of positive squares in only one way, i.e., 164474858025 + 9363271696 = 405555^2 + 96764^2 .

It is not a de Polignac number, because 173838129721 - 2³ = 173838129713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (173838129791) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 122162416 + ... + 122163838.

Almost surely, 2^173838129721 is an apocalyptic number.

173838129721 is the 416939-th square number.

173838129721 is the 208470-th centered octagonal number.

It is an amenable number.

173838129721 is a deficient number, since it is larger than the sum of its proper divisors (717996758).

173838129721 is an frugal number, since it uses more digits than its factorization.

173838129721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3432 (or 1716 counting only the distinct ones).

The product of its digits is 1016064, while the sum is 52.

The spelling of 173838129721 in words is "one hundred seventy-three billion, eight hundred thirty-eight million, one hundred twenty-nine thousand, seven hundred twenty-one".