161824421 has 16 divisors (see below), whose sum is σ = 183220800. Its totient is φ = 141626880.

The previous prime is 161824393. The next prime is 161824447. The reversal of 161824421 is 124428161.

It is a cyclic number.

It is not a de Polignac number, because 161824421 - 2²⁶ = 94715557 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 (161824451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37430 + ... + 41528.

It is an arithmetic number, because the mean of its divisors is an integer number (11451300).

Almost surely, 2^161824421 is an apocalyptic number.

161824421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161824421 is a deficient number, since it is larger than the sum of its proper divisors (21396379).

161824421 is a wasteful number, since it uses less digits than its factorization.

161824421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4244.

The product of its digits is 3072, while the sum is 29.

The square root of 161824421 is about 12721.0227969295. The cubic root of 161824421 is about 544.9391633128.

The spelling of 161824421 in words is "one hundred sixty-one million, eight hundred twenty-four thousand, four hundred twenty-one".