158633221 has 4 divisors (see below), whose sum is σ = 159010444. Its totient is φ = 158256000.

The previous prime is 158633213. The next prime is 158633243. The reversal of 158633221 is 122336851.

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 34644996 + 123988225 = 5886^2 + 11135^2 .

It is a cyclic number.

It is not a de Polignac number, because 158633221 - 2³ = 158633213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (158633291) 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, 187980 + ... + 188821.

It is an arithmetic number, because the mean of its divisors is an integer number (39752611).

Almost surely, 2^158633221 is an apocalyptic number.

It is an amenable number.

158633221 is a deficient number, since it is larger than the sum of its proper divisors (377223).

158633221 is an equidigital number, since it uses as much as digits as its factorization.

158633221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377222.

The product of its digits is 8640, while the sum is 31.

The square root of 158633221 is about 12594.9680825320. The cubic root of 158633221 is about 541.3332635249. Note that the first 3 decimals are identical.

The spelling of 158633221 in words is "one hundred fifty-eight million, six hundred thirty-three thousand, two hundred twenty-one".