21210412 has 6 divisors (see below), whose sum is σ = 37118228. Its totient is φ = 10605204.

The previous prime is 21210389. The next prime is 21210433. The reversal of 21210412 is 21401212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21210392 and 21210401.

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, 2651298 + ... + 2651305.

Almost surely, 2^21210412 is an apocalyptic number.

It is an amenable number.

21210412 is a deficient number, since it is larger than the sum of its proper divisors (15907816).

21210412 is a wasteful number, since it uses less digits than its factorization.

21210412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5302607 (or 5302605 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21210412 is about 4605.4763054433. The cubic root of 21210412 is about 276.8108027849.

Adding to 21210412 its reverse (21401212), we get a palindrome (42611624).

The spelling of 21210412 in words is "twenty-one million, two hundred ten thousand, four hundred twelve".