217138927 has 2 divisors, whose sum is σ = 217138928. Its totient is φ = 217138926.

The previous prime is 217138913. The next prime is 217138963. The reversal of 217138927 is 729831712.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 217138927 - 2⁷ = 217138799 is a prime.

It is a super-2 number, since 2×217138927² = 94298627237422658, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 217138927.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217138997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108569463 + 108569464.

It is an arithmetic number, because the mean of its divisors is an integer number (108569464).

Almost surely, 2^217138927 is an apocalyptic number.

217138927 is a deficient number, since it is larger than the sum of its proper divisors (1).

217138927 is an equidigital number, since it uses as much as digits as its factorization.

217138927 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 40.

The square root of 217138927 is about 14735.6345978041. The cubic root of 217138927 is about 601.0527139457.

The spelling of 217138927 in words is "two hundred seventeen million, one hundred thirty-eight thousand, nine hundred twenty-seven".