217530372 has 12 divisors (see below), whose sum is σ = 507570896. Its totient is φ = 72510120.

The previous prime is 217530367. The next prime is 217530377. The reversal of 217530372 is 273035712.

It is an interprime number because it is at equal distance from previous prime (217530367) and next prime (217530377).

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

It is not an unprimeable number, because it can be changed into a prime (217530377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9063754 + ... + 9063777.

Almost surely, 2^217530372 is an apocalyptic number.

It is an amenable number.

217530372 is an abundant number, since it is smaller than the sum of its proper divisors (290040524).

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

217530372 is a wasteful number, since it uses less digits than its factorization.

217530372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18127538 (or 18127536 counting only the distinct ones).

The product of its (nonzero) digits is 8820, while the sum is 30.

The square root of 217530372 is about 14748.9108750443. The cubic root of 217530372 is about 601.4136776875.

The spelling of 217530372 in words is "two hundred seventeen million, five hundred thirty thousand, three hundred seventy-two".