217097992 has 8 divisors (see below), whose sum is σ = 407058750. Its totient is φ = 108548992.

The previous prime is 217097987. The next prime is 217097999. The reversal of 217097992 is 299790712.

It can be written as a sum of positive squares in only one way, i.e., 135629316 + 81468676 = 11646^2 + 9026^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (217097999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13568617 + ... + 13568632.

Almost surely, 2^217097992 is an apocalyptic number.

It is an amenable number.

217097992 is a deficient number, since it is larger than the sum of its proper divisors (189960758).

217097992 is a wasteful number, since it uses less digits than its factorization.

217097992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27137255 (or 27137251 counting only the distinct ones).

The product of its (nonzero) digits is 142884, while the sum is 46.

The square root of 217097992 is about 14734.2455524536. The cubic root of 217097992 is about 601.0149414476.

It can be divided in two parts, 217097 and 992, that added together give a square (218089 = 467²).

The spelling of 217097992 in words is "two hundred seventeen million, ninety-seven thousand, nine hundred ninety-two".