158730021 has 12 divisors (see below), whose sum is σ = 237183180. Its totient is φ = 102170880.

The previous prime is 158729999. The next prime is 158730029. The reversal of 158730021 is 120037851.

It can be written as a sum of positive squares in 2 ways, for example, as 62964225 + 95765796 = 7935^2 + 9786^2 .

It is not a de Polignac number, because 158730021 - 2¹⁴ = 158713637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (158730029) by changing a digit.

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

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 303820 + ... + 304341.

It is an arithmetic number, because the mean of its divisors is an integer number (19765265).

Almost surely, 2^158730021 is an apocalyptic number.

It is an amenable number.

158730021 is a deficient number, since it is larger than the sum of its proper divisors (78453159).

158730021 is a wasteful number, since it uses less digits than its factorization.

158730021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608196 (or 608193 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 158730021 is about 12598.8103009768. The cubic root of 158730021 is about 541.4433506063.

Adding to 158730021 its reverse (120037851), we get a palindrome (278767872).

The spelling of 158730021 in words is "one hundred fifty-eight million, seven hundred thirty thousand, twenty-one".