21045941 has 6 divisors (see below), whose sum is σ = 24482070. Its totient is φ = 18039336.

The previous prime is 21045917. The next prime is 21045961. The reversal of 21045941 is 14954012.

It can be written as a sum of positive squares in only one way, i.e., 21022225 + 23716 = 4585^2 + 154^2 .

It is not a de Polignac number, because 21045941 - 2¹⁰ = 21044917 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21045941.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21045961) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214706 + ... + 214803.

It is an arithmetic number, because the mean of its divisors is an integer number (4080345).

Almost surely, 2^21045941 is an apocalyptic number.

It is an amenable number.

21045941 is a deficient number, since it is larger than the sum of its proper divisors (3436129).

21045941 is an equidigital number, since it uses as much as digits as its factorization.

21045941 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429523 (or 429516 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 21045941 is about 4587.5855305378. The cubic root of 21045941 is about 276.0934579881.

Adding to 21045941 its reverse (14954012), we get a palindrome (35999953).

The spelling of 21045941 in words is "twenty-one million, forty-five thousand, nine hundred forty-one".