21535204 has 12 divisors (see below), whose sum is σ = 38902528. Its totient is φ = 10420200.

The previous prime is 21535187. The next prime is 21535231. The reversal of 21535204 is 40253512.

It is a super-2 number, since 2×21535204² = 927530022643232, which contains 22 as substring.

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, 86712 + ... + 86959.

Almost surely, 2^21535204 is an apocalyptic number.

It is an amenable number.

21535204 is a deficient number, since it is larger than the sum of its proper divisors (17367324).

21535204 is a wasteful number, since it uses less digits than its factorization.

21535204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173706 (or 173704 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 21535204 is about 4640.6038400191. The cubic root of 21535204 is about 278.2165729519.

Adding to 21535204 its reverse (40253512), we get a palindrome (61788716).

The spelling of 21535204 in words is "twenty-one million, five hundred thirty-five thousand, two hundred four".