16541921 has 4 divisors (see below), whose sum is σ = 18045744. Its totient is φ = 15038100.

The previous prime is 16541909. The next prime is 16541939. The reversal of 16541921 is 12914561.

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 16541921 - 2²² = 12347617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16541981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 751895 + ... + 751916.

It is an arithmetic number, because the mean of its divisors is an integer number (4511436).

Almost surely, 2^16541921 is an apocalyptic number.

16541921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16541921 is a deficient number, since it is larger than the sum of its proper divisors (1503823).

16541921 is a wasteful number, since it uses less digits than its factorization.

16541921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1503822.

The product of its digits is 2160, while the sum is 29.

The square root of 16541921 is about 4067.1760473331. The cubic root of 16541921 is about 254.7975889584.

The spelling of 16541921 in words is "sixteen million, five hundred forty-one thousand, nine hundred twenty-one".