217231280 has 40 divisors (see below), whose sum is σ = 577216032. Its totient is φ = 74479104.

The previous prime is 217231271. The next prime is 217231331. The reversal of 217231280 is 82132712.

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

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193397 + ... + 194516.

Almost surely, 2^217231280 is an apocalyptic number.

217231280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217231280 is an abundant number, since it is smaller than the sum of its proper divisors (359984752).

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

217231280 is a wasteful number, since it uses less digits than its factorization.

217231280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387933 (or 387927 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 217231280 is about 14738.7679267977. The cubic root of 217231280 is about 601.1379146270.

Adding to 217231280 its reverse (82132712), we get a palindrome (299363992).

The spelling of 217231280 in words is "two hundred seventeen million, two hundred thirty-one thousand, two hundred eighty".