211685172 has 12 divisors (see below), whose sum is σ = 493932096. Its totient is φ = 70561720.

The previous prime is 211685147. The next prime is 211685179. The reversal of 211685172 is 271586112.

211685172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×211685172² = 89621224089339168, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211685179) 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, 8820204 + ... + 8820227.

It is an arithmetic number, because the mean of its divisors is an integer number (41161008).

Almost surely, 2^211685172 is an apocalyptic number.

It is an amenable number.

211685172 is an abundant number, since it is smaller than the sum of its proper divisors (282246924).

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

211685172 is a wasteful number, since it uses less digits than its factorization.

211685172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17640438 (or 17640436 counting only the distinct ones).

The product of its digits is 6720, while the sum is 33.

The square root of 211685172 is about 14549.4045238972. The cubic root of 211685172 is about 595.9778868122.

The spelling of 211685172 in words is "two hundred eleven million, six hundred eighty-five thousand, one hundred seventy-two".