21252052 has 18 divisors (see below), whose sum is σ = 37745358. Its totient is φ = 10469952.

The previous prime is 21252047. The next prime is 21252059. The reversal of 21252052 is 25025212.

It can be written as a sum of positive squares in 3 ways, for example, as 8031556 + 13220496 = 2834^2 + 3636^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21252059) 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 5 ways as a sum of consecutive naturals, for example, 20818 + ... + 21814.

Almost surely, 2^21252052 is an apocalyptic number.

It is an amenable number.

21252052 is a deficient number, since it is larger than the sum of its proper divisors (16493306).

21252052 is an equidigital number, since it uses as much as digits as its factorization.

21252052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1147 (or 1072 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 21252052 is about 4609.9947939233. The cubic root of 21252052 is about 276.9918281419.

Adding to 21252052 its reverse (25025212), we get a palindrome (46277264).

The spelling of 21252052 in words is "twenty-one million, two hundred fifty-two thousand, fifty-two".