172009805 has 8 divisors (see below), whose sum is σ = 225176544. Its totient is φ = 125098000.

The previous prime is 172009771. The next prime is 172009807. The reversal of 172009805 is 508900271.

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

It is not a de Polignac number, because 172009805 - 2⁶ = 172009741 is a prime.

It is a super-2 number, since 2×172009805² = 59174746032276050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172009807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1563671 + ... + 1563780.

It is an arithmetic number, because the mean of its divisors is an integer number (28147068).

Almost surely, 2^172009805 is an apocalyptic number.

It is an amenable number.

172009805 is a deficient number, since it is larger than the sum of its proper divisors (53166739).

172009805 is a wasteful number, since it uses less digits than its factorization.

172009805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3127467.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 172009805 is about 13115.2508553973. The cubic root of 172009805 is about 556.1403439949.

The spelling of 172009805 in words is "one hundred seventy-two million, nine thousand, eight hundred five".