158165521 has 2 divisors, whose sum is σ = 158165522. Its totient is φ = 158165520.

The previous prime is 158165429. The next prime is 158165531. The reversal of 158165521 is 125561851.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155975121 + 2190400 = 12489^2 + 1480^2 .

It is a cyclic number.

It is not a de Polignac number, because 158165521 - 2¹⁵ = 158132753 is a prime.

It is not a weakly prime, because it can be changed into another prime (158165531) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79082760 + 79082761.

It is an arithmetic number, because the mean of its divisors is an integer number (79082761).

Almost surely, 2^158165521 is an apocalyptic number.

It is an amenable number.

158165521 is a deficient number, since it is larger than the sum of its proper divisors (1).

158165521 is an equidigital number, since it uses as much as digits as its factorization.

158165521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12000, while the sum is 34.

The square root of 158165521 is about 12576.3874383704. The cubic root of 158165521 is about 540.8007336353.

The spelling of 158165521 in words is "one hundred fifty-eight million, one hundred sixty-five thousand, five hundred twenty-one".