161618082405 has 32 divisors (see below), whose sum is σ = 278500696320. Its totient is φ = 79560023040.

The previous prime is 161618082401. The next prime is 161618082419. The reversal of 161618082405 is 504280816161.

It is not a de Polignac number, because 161618082405 - 2² = 161618082401 is a prime.

It is a super-2 number, since 2×161618082405² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161618082401) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4081341 + ... + 4120749.

It is an arithmetic number, because the mean of its divisors is an integer number (8703146760).

Almost surely, 2^161618082405 is an apocalyptic number.

161618082405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161618082405 is a deficient number, since it is larger than the sum of its proper divisors (116882613915).

161618082405 is a wasteful number, since it uses less digits than its factorization.

161618082405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60461.

The product of its (nonzero) digits is 92160, while the sum is 42.

Adding to 161618082405 its reverse (504280816161), we get a palindrome (665898898566).

The spelling of 161618082405 in words is "one hundred sixty-one billion, six hundred eighteen million, eighty-two thousand, four hundred five".