172897639 has 4 divisors (see below), whose sum is σ = 172930120. Its totient is φ = 172865160.

The previous prime is 172897609. The next prime is 172897657. The reversal of 172897639 is 936798271.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 172897639 - 2¹⁵ = 172864871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172897609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6177 + ... + 19594.

It is an arithmetic number, because the mean of its divisors is an integer number (43232530).

Almost surely, 2^172897639 is an apocalyptic number.

172897639 is a deficient number, since it is larger than the sum of its proper divisors (32481).

172897639 is an equidigital number, since it uses as much as digits as its factorization.

172897639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32480.

The product of its digits is 1143072, while the sum is 52.

The square root of 172897639 is about 13149.0546808506. The cubic root of 172897639 is about 557.0955477095.

The spelling of 172897639 in words is "one hundred seventy-two million, eight hundred ninety-seven thousand, six hundred thirty-nine".