215172 has 36 divisors (see below), whose sum is σ = 560560. Its totient is φ = 69552.

The previous prime is 215161. The next prime is 215179. The reversal of 215172 is 271512.

215172 is nontrivially palindromic in base 11.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

215172 is a Rhonda number in base 16.

It is not an unprimeable number, because it can be changed into a prime (215179) by changing a digit.

215172 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1479 + ... + 1617.

2²¹⁵¹⁷² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280280).

215172 is an abundant number, since it is smaller than the sum of its proper divisors (345388).

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

215172 is a wasteful number, since it uses less digits than its factorization.

215172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 187 counting only the distinct ones).

The product of its digits is 140, while the sum is 18.

The square root of 215172 is about 463.8663600651. The cubic root of 215172 is about 59.9232351612.

Adding to 215172 its reverse (271512), we get a palindrome (486684).

It can be divided in two parts, 21517 and 2, that multiplied together give a palindrome (43034).

The spelling of 215172 in words is "two hundred fifteen thousand, one hundred seventy-two".