158194009 has 4 divisors (see below), whose sum is σ = 158219316. Its totient is φ = 158168704.

The previous prime is 158194007. The next prime is 158194013. The reversal of 158194009 is 900491851.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 900491851 = 7 ⋅128641693.

It can be written as a sum of positive squares in 2 ways, for example, as 28302400 + 129891609 = 5320^2 + 11397^2 .

It is a cyclic number.

It is not a de Polignac number, because 158194009 - 2¹ = 158194007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (158194007) 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, 4257 + ... + 18289.

It is an arithmetic number, because the mean of its divisors is an integer number (39554829).

Almost surely, 2^158194009 is an apocalyptic number.

It is an amenable number.

158194009 is a deficient number, since it is larger than the sum of its proper divisors (25307).

158194009 is a wasteful number, since it uses less digits than its factorization.

158194009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25306.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 158194009 is about 12577.5199860704. The cubic root of 158194009 is about 540.8332004804.

The spelling of 158194009 in words is "one hundred fifty-eight million, one hundred ninety-four thousand, nine".