159968801521 has 9 divisors (see below), whose sum is σ = 162750099961. Its totient is φ = 157234268164.

The previous prime is 159968801519. The next prime is 159968801561. The reversal of 159968801521 is 125108869951.

It is a happy number.

The square root of 159968801521 is 399961.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 159968801521 - 2¹ = 159968801519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (159968801561) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 23594310 + ... + 23601088.

Almost surely, 2^159968801521 is an apocalyptic number.

159968801521 is the 399961-st square number.

159968801521 is the 199981-st centered octagonal number.

It is an amenable number.

159968801521 is a deficient number, since it is larger than the sum of its proper divisors (2781298440).

159968801521 is an frugal number, since it uses more digits than its factorization.

159968801521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13676 (or 6838 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 55.

The spelling of 159968801521 in words is "one hundred fifty-nine billion, nine hundred sixty-eight million, eight hundred one thousand, five hundred twenty-one".