21536330 has 8 divisors (see below), whose sum is σ = 38765412. Its totient is φ = 8614528.

The previous prime is 21536327. The next prime is 21536353. The reversal of 21536330 is 3363512.

It can be written as a sum of positive squares in 2 ways, for example, as 18292729 + 3243601 = 4277^2 + 1801^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21536296 and 21536305.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1076807 + ... + 1076826.

Almost surely, 2^21536330 is an apocalyptic number.

21536330 is a deficient number, since it is larger than the sum of its proper divisors (17229082).

21536330 is a wasteful number, since it uses less digits than its factorization.

21536330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2153640.

The product of its (nonzero) digits is 1620, while the sum is 23.

The square root of 21536330 is about 4640.7251588518. The cubic root of 21536330 is about 278.2214218557.

Adding to 21536330 its reverse (3363512), we get a palindrome (24899842).

The spelling of 21536330 in words is "twenty-one million, five hundred thirty-six thousand, three hundred thirty".