172206639 has 12 divisors (see below), whose sum is σ = 271356072. Its totient is φ = 104367600.

The previous prime is 172206631. The next prime is 172206647. The reversal of 172206639 is 936602271.

172206639 is a `hidden beast` number, since 17 + 2 + 2 + 0 + 6 + 639 = 666.

172206639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (172206631) and next prime (172206647).

It is not a de Polignac number, because 172206639 - 2³ = 172206631 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172206631) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 869632 + ... + 869829.

It is an arithmetic number, because the mean of its divisors is an integer number (22613006).

Almost surely, 2^172206639 is an apocalyptic number.

172206639 is a deficient number, since it is larger than the sum of its proper divisors (99149433).

172206639 is a wasteful number, since it uses less digits than its factorization.

172206639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739478 (or 1739475 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 172206639 is about 13122.7527218949. The cubic root of 172206639 is about 556.3523970226.

The spelling of 172206639 in words is "one hundred seventy-two million, two hundred six thousand, six hundred thirty-nine".