217972 has 6 divisors (see below), whose sum is σ = 381458. Its totient is φ = 108984.

The previous prime is 217969. The next prime is 217979. The reversal of 217972 is 279712.

It is a happy number.

217972 is nontrivially palindromic in base 6.

It can be written as a sum of positive squares in only one way, i.e., 163216 + 54756 = 404^2 + 234^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 217972.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27243 + ... + 27250.

2²¹⁷⁹⁷² is an apocalyptic number.

It is an amenable number.

217972 is a deficient number, since it is larger than the sum of its proper divisors (163486).

217972 is a wasteful number, since it uses less digits than its factorization.

217972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54497 (or 54495 counting only the distinct ones).

The product of its digits is 1764, while the sum is 28.

The square root of 217972 is about 466.8747155287. The cubic root of 217972 is about 60.1820397263.

The spelling of 217972 in words is "two hundred seventeen thousand, nine hundred seventy-two".