158928021 has 48 divisors (see below), whose sum is σ = 276688000. Its totient is φ = 90122760.

The previous prime is 158928017. The next prime is 158928023. The reversal of 158928021 is 120829851.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is not a de Polignac number, because 158928021 - 2² = 158928017 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 (158928023) 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 47 ways as a sum of consecutive naturals, for example, 1213126 + ... + 1213256.

Almost surely, 2^158928021 is an apocalyptic number.

It is an amenable number.

158928021 is a deficient number, since it is larger than the sum of its proper divisors (117759979).

158928021 is an frugal number, since it uses more digits than its factorization.

158928021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 158928021 is about 12606.6657368235. The cubic root of 158928021 is about 541.6683894015.

The spelling of 158928021 in words is "one hundred fifty-eight million, nine hundred twenty-eight thousand, twenty-one".