172220785 has 32 divisors (see below), whose sum is σ = 230480640. Its totient is φ = 122496000.

The previous prime is 172220777. The next prime is 172220809. The reversal of 172220785 is 587022271.

It is not a de Polignac number, because 172220785 - 2³ = 172220777 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 172220785.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 739029 + ... + 739261.

It is an arithmetic number, because the mean of its divisors is an integer number (7202520).

Almost surely, 2^172220785 is an apocalyptic number.

It is an amenable number.

172220785 is a deficient number, since it is larger than the sum of its proper divisors (58259855).

172220785 is a wasteful number, since it uses less digits than its factorization.

172220785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489.

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 172220785 is about 13123.2916983507. The cubic root of 172220785 is about 556.3676305535.

The spelling of 172220785 in words is "one hundred seventy-two million, two hundred twenty thousand, seven hundred eighty-five".