21210052 has 12 divisors (see below), whose sum is σ = 37149840. Its totient is φ = 10595816.

The previous prime is 21210041. The next prime is 21210053. The reversal of 21210052 is 25001212.

It is not an unprimeable number, because it can be changed into a prime (21210053) by changing a digit.

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, 7899 + ... + 10237.

It is an arithmetic number, because the mean of its divisors is an integer number (3095820).

Almost surely, 2^21210052 is an apocalyptic number.

It is an amenable number.

21210052 is a deficient number, since it is larger than the sum of its proper divisors (15939788).

21210052 is a wasteful number, since it uses less digits than its factorization.

21210052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4610 (or 4608 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 21210052 is about 4605.4372213721. The cubic root of 21210052 is about 276.8092366916.

Adding to 21210052 its reverse (25001212), we get a palindrome (46211264).

The spelling of 21210052 in words is "twenty-one million, two hundred ten thousand, fifty-two".