21536066 has 8 divisors (see below), whose sum is σ = 32323980. Its totient is φ = 10761408.

The previous prime is 21536033. The next prime is 21536069. The reversal of 21536066 is 66063512.

It can be written as a sum of positive squares in 2 ways, for example, as 20025625 + 1510441 = 4475^2 + 1229^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21536069) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3830 + ... + 7598.

Almost surely, 2^21536066 is an apocalyptic number.

21536066 is a deficient number, since it is larger than the sum of its proper divisors (10787914).

21536066 is a wasteful number, since it uses less digits than its factorization.

21536066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6628.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 21536066 is about 4640.6967149341. The cubic root of 21536066 is about 278.2202850053.

Adding to 21536066 its reverse (66063512), we get a palindrome (87599578).

The spelling of 21536066 in words is "twenty-one million, five hundred thirty-six thousand, sixty-six".