220643172 has 18 divisors (see below), whose sum is σ = 557736998. Its totient is φ = 73547712.

The previous prime is 220643083. The next prime is 220643183. The reversal of 220643172 is 271346022.

220643172 is a `hidden beast` number, since 2 + 2 + 0 + 643 + 17 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 137030436 + 83612736 = 11706^2 + 9144^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3064453 + ... + 3064524.

Almost surely, 2^220643172 is an apocalyptic number.

It is an amenable number.

220643172 is an abundant number, since it is smaller than the sum of its proper divisors (337093826).

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

220643172 is a wasteful number, since it uses less digits than its factorization.

220643172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6128987 (or 6128982 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 220643172 is about 14854.0624746229. The cubic root of 220643172 is about 604.2687903553.

Adding to 220643172 its reverse (271346022), we get a palindrome (491989194).

The spelling of 220643172 in words is "two hundred twenty million, six hundred forty-three thousand, one hundred seventy-two".