158643209 has 4 divisors (see below), whose sum is σ = 160278804. Its totient is φ = 157007616.

The previous prime is 158643197. The next prime is 158643223. The reversal of 158643209 is 902346851.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52243984 + 106399225 = 7228^2 + 10315^2 .

It is a cyclic number.

It is not a de Polignac number, because 158643209 - 2²⁴ = 141865993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (158646209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 817652 + ... + 817845.

It is an arithmetic number, because the mean of its divisors is an integer number (40069701).

Almost surely, 2^158643209 is an apocalyptic number.

It is an amenable number.

158643209 is a deficient number, since it is larger than the sum of its proper divisors (1635595).

158643209 is an equidigital number, since it uses as much as digits as its factorization.

158643209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1635594.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 158643209 is about 12595.3645838459. The cubic root of 158643209 is about 541.3446245818.

The spelling of 158643209 in words is "one hundred fifty-eight million, six hundred forty-three thousand, two hundred nine".