21336057 has 6 divisors (see below), whose sum is σ = 30818762. Its totient is φ = 14224032.

The previous prime is 21336047. The next prime is 21336061. The reversal of 21336057 is 75063312.

It is a happy number.

21336057 is a `hidden beast` number, since 21 + 33 + 605 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18224361 + 3111696 = 4269^2 + 1764^2 .

It is not a de Polignac number, because 21336057 - 2⁸ = 21335801 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 21336057.

It is not an unprimeable number, because it can be changed into a prime (21336017) 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, 1185328 + ... + 1185345.

Almost surely, 2^21336057 is an apocalyptic number.

It is an amenable number.

21336057 is a deficient number, since it is larger than the sum of its proper divisors (9482705).

21336057 is a wasteful number, since it uses less digits than its factorization.

21336057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2370679 (or 2370676 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 27.

The square root of 21336057 is about 4619.0969896723. The cubic root of 21336057 is about 277.3563122692.

Adding to 21336057 its reverse (75063312), we get a palindrome (96399369).

The spelling of 21336057 in words is "twenty-one million, three hundred thirty-six thousand, fifty-seven".