159749821 has 16 divisors (see below), whose sum is σ = 199899648. Its totient is φ = 124023600.

The previous prime is 159749813. The next prime is 159749857. The reversal of 159749821 is 128947951.

It is a cyclic number.

It is not a de Polignac number, because 159749821 - 2³ = 159749813 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 (159749801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18126 + ... + 25456.

It is an arithmetic number, because the mean of its divisors is an integer number (12493728).

Almost surely, 2^159749821 is an apocalyptic number.

159749821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

159749821 is a deficient number, since it is larger than the sum of its proper divisors (40149827).

159749821 is a wasteful number, since it uses less digits than its factorization.

159749821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7632.

The product of its digits is 181440, while the sum is 46.

The square root of 159749821 is about 12639.2175786320. The cubic root of 159749821 is about 542.6004214278.

The spelling of 159749821 in words is "one hundred fifty-nine million, seven hundred forty-nine thousand, eight hundred twenty-one".