165501511011 has 24 divisors (see below), whose sum is σ = 247959449920. Its totient is φ = 110313102312.

The previous prime is 165501510997. The next prime is 165501511037. The reversal of 165501511011 is 110115105561.

165501511011 is a `hidden beast` number, since 1 + 6 + 5 + 501 + 51 + 101 + 1 = 666.

It is not a de Polignac number, because 165501511011 - 2⁶ = 165501510947 is a prime.

It is a super-4 number, since 4×165501511011⁴ (a number of 46 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165501511211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1253976 + ... + 1379658.

Almost surely, 2^165501511011 is an apocalyptic number.

165501511011 is a deficient number, since it is larger than the sum of its proper divisors (82457938909).

165501511011 is an equidigital number, since it uses as much as digits as its factorization.

165501511011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131117 (or 131105 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 27.

Adding to 165501511011 its reverse (110115105561), we get a palindrome (275616616572).

The spelling of 165501511011 in words is "one hundred sixty-five billion, five hundred one million, five hundred eleven thousand, eleven".