217381164 has 96 divisors (see below), whose sum is σ = 681063936. Its totient is φ = 52116480.

The previous prime is 217381163. The next prime is 217381183. The reversal of 217381164 is 461183712.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (217381163) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2964 + ... + 21060.

It is an arithmetic number, because the mean of its divisors is an integer number (7094416).

Almost surely, 2^217381164 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 217381164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (340531968).

217381164 is an abundant number, since it is smaller than the sum of its proper divisors (463682772).

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

217381164 is a wasteful number, since it uses less digits than its factorization.

217381164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18135 (or 18133 counting only the distinct ones).

The product of its digits is 8064, while the sum is 33.

The square root of 217381164 is about 14743.8517355540. The cubic root of 217381164 is about 601.2761394116.

The spelling of 217381164 in words is "two hundred seventeen million, three hundred eighty-one thousand, one hundred sixty-four".