172056551209 has 27 divisors (see below), whose sum is σ = 180220322583. Its totient is φ = 164259612000.

The previous prime is 172056551207. The next prime is 172056551213. The reversal of 172056551209 is 902155650271.

The square root of 172056551209 is 414797.

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., 8290648809 + 163765902400 = 91053^2 + 404680^2 .

It is not a de Polignac number, because 172056551209 - 2¹ = 172056551207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172056551201) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1139447284 + ... + 1139447434.

Almost surely, 2^172056551209 is an apocalyptic number.

172056551209 is the 414797-th square number.

172056551209 is the 207399-th centered octagonal number.

It is an amenable number.

172056551209 is a deficient number, since it is larger than the sum of its proper divisors (8163771374).

172056551209 is an frugal number, since it uses more digits than its factorization.

172056551209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518 (or 259 counting only the distinct ones).

The product of its (nonzero) digits is 189000, while the sum is 43.

The spelling of 172056551209 in words is "one hundred seventy-two billion, fifty-six million, five hundred fifty-one thousand, two hundred nine".