111635506161 has 9 divisors (see below), whose sum is σ = 161252734539. Its totient is φ = 74423002536.

The previous prime is 111635506063. The next prime is 111635506181. The reversal of 111635506161 is 161605536111.

The square root of 111635506161 is 334119.

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

111635506161 is a `hidden beast` number, since 1 + 1 + 1 + 6 + 35 + 5 + 0 + 616 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 109703376225 + 1932129936 = 331215^2 + 43956^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is a de Polignac number, because none of the positive numbers 2^k-111635506161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (111635506181) 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, 946671 + ... + 1058043.

Almost surely, 2^111635506161 is an apocalyptic number.

111635506161 is the 334119-th square number.

111635506161 is the 167060-th centered octagonal number.

It is an amenable number.

111635506161 is a deficient number, since it is larger than the sum of its proper divisors (49617228378).

111635506161 is an frugal number, since it uses more digits than its factorization.

111635506161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222752 (or 111376 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

Multiplying 111635506161 by its sum of digits (36), we get a square (4018878221796 = 2004714²).

It can be divided in two parts, 111635 and 506161, that added together give a square (617796 = 786²).

The spelling of 111635506161 in words is "one hundred eleven billion, six hundred thirty-five million, five hundred six thousand, one hundred sixty-one".