172017720 has 96 divisors (see below), whose sum is σ = 638932320. Its totient is φ = 39317760.

The previous prime is 172017709. The next prime is 172017731. The reversal of 172017720 is 27710271.

It is an interprime number because it is at equal distance from previous prime (172017709) and next prime (172017731).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31611 + ... + 36650.

It is an arithmetic number, because the mean of its divisors is an integer number (6655545).

Almost surely, 2^172017720 is an apocalyptic number.

172017720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

172017720 is an abundant number, since it is smaller than the sum of its proper divisors (466914600).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

172017720 is a wasteful number, since it uses less digits than its factorization.

172017720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68285 (or 68278 counting only the distinct ones).

The product of its (nonzero) digits is 1372, while the sum is 27.

The square root of 172017720 is about 13115.5525998717. The cubic root of 172017720 is about 556.1488740964.

Adding to 172017720 its reverse (27710271), we get a palindrome (199727991).

The spelling of 172017720 in words is "one hundred seventy-two million, seventeen thousand, seven hundred twenty".