21210512 has 10 divisors (see below), whose sum is σ = 41095398. Its totient is φ = 10605248.

The previous prime is 21210499. The next prime is 21210521. The reversal of 21210512 is 21501212.

It can be written as a sum of positive squares in only one way, i.e., 16613776 + 4596736 = 4076^2 + 2144^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 662813 + ... + 662844.

Almost surely, 2^21210512 is an apocalyptic number.

It is an amenable number.

21210512 is a deficient number, since it is larger than the sum of its proper divisors (19884886).

21210512 is a wasteful number, since it uses less digits than its factorization.

21210512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1325665 (or 1325659 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 21210512 is about 4605.4871620709. The cubic root of 21210512 is about 276.8112378076.

Adding to 21210512 its reverse (21501212), we get a palindrome (42711724).

The spelling of 21210512 in words is "twenty-one million, two hundred ten thousand, five hundred twelve".