217278960 has 40 divisors (see below), whose sum is σ = 673565520. Its totient is φ = 57940992.

The previous prime is 217278949. The next prime is 217278961. The reversal of 217278960 is 69872712.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217278961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 452425 + ... + 452904.

It is an arithmetic number, because the mean of its divisors is an integer number (16839138).

Almost surely, 2^217278960 is an apocalyptic number.

217278960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217278960 is an abundant number, since it is smaller than the sum of its proper divisors (456286560).

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

217278960 is a wasteful number, since it uses less digits than its factorization.

217278960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905345 (or 905339 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 42.

The square root of 217278960 is about 14740.3853409604. The cubic root of 217278960 is about 601.1818925768.

The spelling of 217278960 in words is "two hundred seventeen million, two hundred seventy-eight thousand, nine hundred sixty".