1720879583329 has 9 divisors (see below), whose sum is σ = 1729919141587. Its totient is φ = 1711887036664.

The previous prime is 1720879583321. The next prime is 1720879583341. The reversal of 1720879583329 is 9233859780271.

It is a happy number.

The square root of 1720879583329 is 1311823.

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., 1686115235025 + 34764348304 = 1298505^2 + 186452^2 .

It is not a de Polignac number, because 1720879583329 - 2³ = 1720879583321 is a prime.

It is a super-2 number, since 2×1720879583329² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1720879583321) 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, 258425802 + ... + 258432460.

Almost surely, 2^{1720879583329} is an apocalyptic number.

1720879583329 is the 1311823-rd square number.

1720879583329 is the 655912-nd centered octagonal number.

It is an amenable number.

1720879583329 is a deficient number, since it is larger than the sum of its proper divisors (9039558258).

1720879583329 is an frugal number, since it uses more digits than its factorization.

1720879583329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13712 (or 6856 counting only the distinct ones).

The product of its (nonzero) digits is 45722880, while the sum is 64.

Multiplying 1720879583329 by its sum of digits (64), we get a square (110136293333056 = 10494584²).

The spelling of 1720879583329 in words is "one trillion, seven hundred twenty billion, eight hundred seventy-nine million, five hundred eighty-three thousand, three hundred twenty-nine".