21541204 has 12 divisors (see below), whose sum is σ = 38121300. Its totient is φ = 10649408.

The previous prime is 21541183. The next prime is 21541211. The reversal of 21541204 is 40214512.

It can be written as a sum of positive squares in 2 ways, for example, as 13690000 + 7851204 = 3700^2 + 2802^2 .

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, 29899 + ... + 30610.

It is an arithmetic number, because the mean of its divisors is an integer number (3176775).

Almost surely, 2^21541204 is an apocalyptic number.

It is an amenable number.

21541204 is a deficient number, since it is larger than the sum of its proper divisors (16580096).

21541204 is a wasteful number, since it uses less digits than its factorization.

21541204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60602 (or 60600 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 21541204 is about 4641.2502625909. The cubic root of 21541204 is about 278.2424088565.

Adding to 21541204 its reverse (40214512), we get a palindrome (61755716).

The spelling of 21541204 in words is "twenty-one million, five hundred forty-one thousand, two hundred four".