172809947 has 8 divisors (see below), whose sum is σ = 183117312. Its totient is φ = 162518400.

The previous prime is 172809941. The next prime is 172809979. The reversal of 172809947 is 749908271.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 172809947 - 2²⁰ = 171761371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172809941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24422 + ... + 30692.

It is an arithmetic number, because the mean of its divisors is an integer number (22889664).

Almost surely, 2^172809947 is an apocalyptic number.

172809947 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

172809947 is a deficient number, since it is larger than the sum of its proper divisors (10307365).

172809947 is a wasteful number, since it uses less digits than its factorization.

172809947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7909.

The product of its (nonzero) digits is 254016, while the sum is 47.

The square root of 172809947 is about 13145.7197216432. The cubic root of 172809947 is about 557.0013473016.

The spelling of 172809947 in words is "one hundred seventy-two million, eight hundred nine thousand, nine hundred forty-seven".