159798781021 has 16 divisors (see below), whose sum is σ = 183607295040. Its totient is φ = 137546017920.

The previous prime is 159798781007. The next prime is 159798781057. The reversal of 159798781021 is 120187897951.

It is a cyclic number.

It is not a de Polignac number, because 159798781021 - 2⁷ = 159798780893 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 (159798781091) 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, 141601 + ... + 582793.

It is an arithmetic number, because the mean of its divisors is an integer number (11475455940).

Almost surely, 2^159798781021 is an apocalyptic number.

159798781021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

159798781021 is a deficient number, since it is larger than the sum of its proper divisors (23808514019).

159798781021 is a wasteful number, since it uses less digits than its factorization.

159798781021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442956.

The product of its (nonzero) digits is 2540160, while the sum is 58.

The spelling of 159798781021 in words is "one hundred fifty-nine billion, seven hundred ninety-eight million, seven hundred eighty-one thousand, twenty-one".