21041205 has 32 divisors (see below), whose sum is σ = 35665920. Its totient is φ = 10570560.

The previous prime is 21041203. The next prime is 21041213. The reversal of 21041205 is 50214012.

It is not a de Polignac number, because 21041205 - 2¹ = 21041203 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21041201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24066 + ... + 24924.

It is an arithmetic number, because the mean of its divisors is an integer number (1114560).

Almost surely, 2^21041205 is an apocalyptic number.

It is an amenable number.

21041205 is a deficient number, since it is larger than the sum of its proper divisors (14624715).

21041205 is a wasteful number, since it uses less digits than its factorization.

21041205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 961.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 21041205 is about 4587.0693258332. The cubic root of 21041205 is about 276.0727465247.

Adding to 21041205 its reverse (50214012), we get a palindrome (71255217).

The spelling of 21041205 in words is "twenty-one million, forty-one thousand, two hundred five".