217280431 has 2 divisors, whose sum is σ = 217280432. Its totient is φ = 217280430.

The previous prime is 217280429. The next prime is 217280473. The reversal of 217280431 is 134082712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 217280431 - 2¹ = 217280429 is a prime.

It is a super-2 number, since 2×217280431² = 94421571391091522, which contains 22 as substring.

Together with 217280429, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 217280431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217280831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108640215 + 108640216.

It is an arithmetic number, because the mean of its divisors is an integer number (108640216).

Almost surely, 2^217280431 is an apocalyptic number.

217280431 is a deficient number, since it is larger than the sum of its proper divisors (1).

217280431 is an equidigital number, since it uses as much as digits as its factorization.

217280431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 217280431 is about 14740.4352378076. The cubic root of 217280431 is about 601.1832492606.

The spelling of 217280431 in words is "two hundred seventeen million, two hundred eighty thousand, four hundred thirty-one".