165517955281 has 64 divisors (see below), whose sum is σ = 199600128000. Its totient is φ = 134344894464.

The previous prime is 165517955263. The next prime is 165517955293. The reversal of 165517955281 is 182559715561.

It is not a de Polignac number, because 165517955281 - 2¹⁹ = 165517430993 is a prime.

It is a super-2 number, since 2×165517955281² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (165517955201) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 425495835 + ... + 425496223.

It is an arithmetic number, because the mean of its divisors is an integer number (3118752000).

Almost surely, 2^165517955281 is an apocalyptic number.

It is an amenable number.

165517955281 is a deficient number, since it is larger than the sum of its proper divisors (34082172719).

165517955281 is a wasteful number, since it uses less digits than its factorization.

165517955281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806.

The product of its digits is 3780000, while the sum is 55.

The spelling of 165517955281 in words is "one hundred sixty-five billion, five hundred seventeen million, nine hundred fifty-five thousand, two hundred eighty-one".