18125506161 has 45 divisors (see below), whose sum is σ = 31511751579. Its totient is φ = 10352585376.

The previous prime is 18125506159. The next prime is 18125506163. The reversal of 18125506161 is 16160552181.

The square root of 18125506161 is 134631.

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

18125506161 is a `hidden beast` number, since 18 + 1 + 25 + 5 + 0 + 616 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (18125506159) and next prime (18125506163).

It can be written as a sum of positive squares in only one way, i.e., 821682225 + 17303823936 = 28665^2 + 131544^2 .

It is not a de Polignac number, because 18125506161 - 2¹ = 18125506159 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18125506163) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 8480685 + ... + 8482821.

Almost surely, 2^18125506161 is an apocalyptic number.

18125506161 is the 134631-st square number.

18125506161 is the 67316-th centered octagonal number.

It is an amenable number.

18125506161 is a deficient number, since it is larger than the sum of its proper divisors (13386245418).

18125506161 is an frugal number, since it uses more digits than its factorization.

18125506161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4300 (or 2147 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 36.

Multiplying 18125506161 by its sum of digits (36), we get a square (652518221796 = 807786²).

Multiplying 18125506161 by its product of nonzero digits (14400), we get a square (261007288718400 = 16155720²).

The spelling of 18125506161 in words is "eighteen billion, one hundred twenty-five million, five hundred six thousand, one hundred sixty-one".