21541384 has 16 divisors (see below), whose sum is σ = 40460220. Its totient is φ = 10752000.

The previous prime is 21541379. The next prime is 21541391. The reversal of 21541384 is 48314512.

It can be written as a sum of positive squares in 2 ways, for example, as 18576100 + 2965284 = 4310^2 + 1722^2 .

It is a super-3 number, since 3×21541384³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3384 + ... + 7384.

Almost surely, 2^21541384 is an apocalyptic number.

It is an amenable number.

21541384 is a deficient number, since it is larger than the sum of its proper divisors (18918836).

21541384 is a wasteful number, since it uses less digits than its factorization.

21541384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4680 (or 4676 counting only the distinct ones).

The product of its digits is 3840, while the sum is 28.

The square root of 21541384 is about 4641.2696538771. The cubic root of 21541384 is about 278.2431838595.

Adding to 21541384 its reverse (48314512), we get a palindrome (69855896).

The spelling of 21541384 in words is "twenty-one million, five hundred forty-one thousand, three hundred eighty-four".