161405 has 8 divisors (see below), whose sum is σ = 204000. Its totient is φ = 122256.

The previous prime is 161387. The next prime is 161407. The reversal of 161405 is 504161.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161405 - 2⁶ = 161341 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 161405.

It is not an unprimeable number, because it can be changed into a prime (161407) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 755 + ... + 944.

It is an arithmetic number, because the mean of its divisors is an integer number (25500).

2¹⁶¹⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

161405 is a deficient number, since it is larger than the sum of its proper divisors (42595).

161405 is a wasteful number, since it uses less digits than its factorization.

161405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1723.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 161405 is about 401.7524113182. The cubic root of 161405 is about 54.4467959865.

Adding to 161405 its reverse (504161), we get a palindrome (665566).

The spelling of 161405 in words is "one hundred sixty-one thousand, four hundred five".