21207652 has 6 divisors (see below), whose sum is σ = 37113398. Its totient is φ = 10603824.

The previous prime is 21207649. The next prime is 21207673. The reversal of 21207652 is 25670212.

It can be written as a sum of positive squares in only one way, i.e., 16516096 + 4691556 = 4064^2 + 2166^2 .

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 as a sum of consecutive naturals, namely, 2650953 + ... + 2650960.

Almost surely, 2^21207652 is an apocalyptic number.

It is an amenable number.

21207652 is a deficient number, since it is larger than the sum of its proper divisors (15905746).

21207652 is a wasteful number, since it uses less digits than its factorization.

21207652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5301917 (or 5301915 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21207652 is about 4605.1766524206. The cubic root of 21207652 is about 276.7987956166.

Adding to 21207652 its reverse (25670212), we get a palindrome (46877864).

The spelling of 21207652 in words is "twenty-one million, two hundred seven thousand, six hundred fifty-two".