158217509 has 2 divisors, whose sum is σ = 158217510. Its totient is φ = 158217508.

The previous prime is 158217497. The next prime is 158217517. The reversal of 158217509 is 905712851.

158217509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 157000900 + 1216609 = 12530^2 + 1103^2 .

It is a cyclic number.

It is not a de Polignac number, because 158217509 - 2²⁴ = 141440293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (158217539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79108754 + 79108755.

It is an arithmetic number, because the mean of its divisors is an integer number (79108755).

Almost surely, 2^158217509 is an apocalyptic number.

It is an amenable number.

158217509 is a deficient number, since it is larger than the sum of its proper divisors (1).

158217509 is an equidigital number, since it uses as much as digits as its factorization.

158217509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25200, while the sum is 38.

The square root of 158217509 is about 12578.4541578049. The cubic root of 158217509 is about 540.8599797308.

It can be divided in two parts, 1582 and 17509, that added together give a palindrome (19091).

The spelling of 158217509 in words is "one hundred fifty-eight million, two hundred seventeen thousand, five hundred nine".