158315221 has 2 divisors, whose sum is σ = 158315222. Its totient is φ = 158315220.

The previous prime is 158315159. The next prime is 158315249. The reversal of 158315221 is 122513851.

It is an a-pointer prime, because the next prime (158315249) can be obtained adding 158315221 to its sum of digits (28).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 135140625 + 23174596 = 11625^2 + 4814^2 .

It is a cyclic number.

It is not a de Polignac number, because 158315221 - 2⁷ = 158315093 is a prime.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 158315221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (158315251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79157610 + 79157611.

It is an arithmetic number, because the mean of its divisors is an integer number (79157611).

Almost surely, 2^158315221 is an apocalyptic number.

It is an amenable number.

158315221 is a deficient number, since it is larger than the sum of its proper divisors (1).

158315221 is an equidigital number, since it uses as much as digits as its factorization.

158315221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 28.

The square root of 158315221 is about 12582.3376603873. The cubic root of 158315221 is about 540.9712982884.

The spelling of 158315221 in words is "one hundred fifty-eight million, three hundred fifteen thousand, two hundred twenty-one".