21541372 has 24 divisors (see below), whose sum is σ = 38772720. Its totient is φ = 10467840.

The previous prime is 21541361. The next prime is 21541379. The reversal of 21541372 is 27314512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541379) 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 7 ways as a sum of consecutive naturals, for example, 22422 + ... + 23362.

It is an arithmetic number, because the mean of its divisors is an integer number (1615530).

Almost surely, 2^21541372 is an apocalyptic number.

It is an amenable number.

21541372 is a deficient number, since it is larger than the sum of its proper divisors (17231348).

21541372 is a wasteful number, since it uses less digits than its factorization.

21541372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101 (or 1099 counting only the distinct ones).

The product of its digits is 1680, while the sum is 25.

The square root of 21541372 is about 4641.2683611272. The cubic root of 21541372 is about 278.2431321928.

Adding to 21541372 its reverse (27314512), we get a palindrome (48855884).

The spelling of 21541372 in words is "twenty-one million, five hundred forty-one thousand, three hundred seventy-two".