21006052 has 6 divisors (see below), whose sum is σ = 36760598. Its totient is φ = 10503024.

The previous prime is 21006019. The next prime is 21006053. The reversal of 21006052 is 25060012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 14318656 + 6687396 = 3784^2 + 2586^2 .

It is not an unprimeable number, because it can be changed into a prime (21006053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2625753 + ... + 2625760.

Almost surely, 2^21006052 is an apocalyptic number.

It is an amenable number.

21006052 is a deficient number, since it is larger than the sum of its proper divisors (15754546).

21006052 is a wasteful number, since it uses less digits than its factorization.

21006052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5251517 (or 5251515 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21006052 is about 4583.2359747235. The cubic root of 21006052 is about 275.9189182816.

Adding to 21006052 its reverse (25060012), we get a palindrome (46066064).

The spelling of 21006052 in words is "twenty-one million, six thousand, fifty-two".