21036051 has 16 divisors (see below), whose sum is σ = 31235200. Its totient is φ = 13992264.

The previous prime is 21036031. The next prime is 21036061. The reversal of 21036051 is 15063012.

It is not a de Polignac number, because 21036051 - 2¹¹ = 21034003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21036031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22740 + ... + 23646.

It is an arithmetic number, because the mean of its divisors is an integer number (1952200).

Almost surely, 2^21036051 is an apocalyptic number.

21036051 is a deficient number, since it is larger than the sum of its proper divisors (10199149).

21036051 is an equidigital number, since it uses as much as digits as its factorization.

21036051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1775 (or 1769 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 21036051 is about 4586.5074948156. The cubic root of 21036051 is about 276.0502035330.

Adding to 21036051 its reverse (15063012), we get a palindrome (36099063).

The spelling of 21036051 in words is "twenty-one million, thirty-six thousand, fifty-one".