161105421 has 4 divisors (see below), whose sum is σ = 214807232. Its totient is φ = 107403612.

The previous prime is 161105387. The next prime is 161105429. The reversal of 161105421 is 124501161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 161105421 - 2¹⁴ = 161089037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161105429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26850901 + ... + 26850906.

It is an arithmetic number, because the mean of its divisors is an integer number (53701808).

Almost surely, 2^161105421 is an apocalyptic number.

It is an amenable number.

161105421 is a deficient number, since it is larger than the sum of its proper divisors (53701811).

161105421 is an equidigital number, since it uses as much as digits as its factorization.

161105421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53701810.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 161105421 is about 12692.7310300030. The cubic root of 161105421 is about 544.1308943332.

Adding to 161105421 its reverse (124501161), we get a palindrome (285606582).

The spelling of 161105421 in words is "one hundred sixty-one million, one hundred five thousand, four hundred twenty-one".