159928021 has 4 divisors (see below), whose sum is σ = 174466944. Its totient is φ = 145389100.

The previous prime is 159928009. The next prime is 159928033. The reversal of 159928021 is 120829951.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120829951 = 11 ⋅10984541.

It is an interprime number because it is at equal distance from previous prime (159928009) and next prime (159928033).

It is a cyclic number.

It is not a de Polignac number, because 159928021 - 2¹³ = 159919829 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 (159928081) 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 3 ways as a sum of consecutive naturals, for example, 7269445 + ... + 7269466.

It is an arithmetic number, because the mean of its divisors is an integer number (43616736).

Almost surely, 2^159928021 is an apocalyptic number.

159928021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

159928021 is a deficient number, since it is larger than the sum of its proper divisors (14538923).

159928021 is a wasteful number, since it uses less digits than its factorization.

159928021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14538922.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 159928021 is about 12646.2651008114. The cubic root of 159928021 is about 542.8021023308.

The spelling of 159928021 in words is "one hundred fifty-nine million, nine hundred twenty-eight thousand, twenty-one".