21421053 has 12 divisors (see below), whose sum is σ = 32008860. Its totient is φ = 13788096.

The previous prime is 21421051. The next prime is 21421061. The reversal of 21421053 is 35012412.

It can be written as a sum of positive squares in 2 ways, for example, as 3755844 + 17665209 = 1938^2 + 4203^2 .

It is not a de Polignac number, because 21421053 - 2¹ = 21421051 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40776 + ... + 41297.

It is an arithmetic number, because the mean of its divisors is an integer number (2667405).

Almost surely, 2^21421053 is an apocalyptic number.

It is an amenable number.

21421053 is a deficient number, since it is larger than the sum of its proper divisors (10587807).

21421053 is a wasteful number, since it uses less digits than its factorization.

21421053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82108 (or 82105 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21421053 is about 4628.2883445179. The cubic root of 21421053 is about 277.7241237823.

Adding to 21421053 its reverse (35012412), we get a palindrome (56433465).

The spelling of 21421053 in words is "twenty-one million, four hundred twenty-one thousand, fifty-three".