16043421 has 4 divisors (see below), whose sum is σ = 21391232. Its totient is φ = 10695612.

The previous prime is 16043389. The next prime is 16043431. The reversal of 16043421 is 12434061.

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 16043421 - 2⁵ = 16043389 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16043431) 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, 2673901 + ... + 2673906.

It is an arithmetic number, because the mean of its divisors is an integer number (5347808).

Almost surely, 2^16043421 is an apocalyptic number.

It is an amenable number.

16043421 is a deficient number, since it is larger than the sum of its proper divisors (5347811).

16043421 is an equidigital number, since it uses as much as digits as its factorization.

16043421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5347810.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 16043421 is about 4005.4239475991. The cubic root of 16043421 is about 252.2119500547.

Adding to 16043421 its reverse (12434061), we get a palindrome (28477482).

The spelling of 16043421 in words is "sixteen million, forty-three thousand, four hundred twenty-one".