217392139 has 2 divisors, whose sum is σ = 217392140. Its totient is φ = 217392138.

The previous prime is 217392101. The next prime is 217392163. The reversal of 217392139 is 931293712.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217392139 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 217392098 and 217392107.

It is not a weakly prime, because it can be changed into another prime (217392199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108696069 + 108696070.

It is an arithmetic number, because the mean of its divisors is an integer number (108696070).

Almost surely, 2^217392139 is an apocalyptic number.

217392139 is a deficient number, since it is larger than the sum of its proper divisors (1).

217392139 is an equidigital number, since it uses as much as digits as its factorization.

217392139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20412, while the sum is 37.

The square root of 217392139 is about 14744.2239198949. The cubic root of 217392139 is about 601.2862581886.

The spelling of 217392139 in words is "two hundred seventeen million, three hundred ninety-two thousand, one hundred thirty-nine".