21541044 has 24 divisors (see below), whose sum is σ = 57443008. Its totient is φ = 6154560.

The previous prime is 21541043. The next prime is 21541049. The reversal of 21541044 is 44014512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21541044.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128137 + ... + 128304.

Almost surely, 2^21541044 is an apocalyptic number.

It is an amenable number.

21541044 is an abundant number, since it is smaller than the sum of its proper divisors (35901964).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21541044 is a wasteful number, since it uses less digits than its factorization.

21541044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256455 (or 256453 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 21541044 is about 4641.2330258241. The cubic root of 21541044 is about 278.2417199613.

Adding to 21541044 its reverse (44014512), we get a palindrome (65555556).

The spelling of 21541044 in words is "twenty-one million, five hundred forty-one thousand, forty-four".