21000412 has 12 divisors (see below), whose sum is σ = 37216480. Its totient is φ = 10367136.

The previous prime is 21000407. The next prime is 21000433. The reversal of 21000412 is 21400012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32913 + ... + 33544.

Almost surely, 2^21000412 is an apocalyptic number.

It is an amenable number.

21000412 is a deficient number, since it is larger than the sum of its proper divisors (16216068).

21000412 is a wasteful number, since it uses less digits than its factorization.

21000412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66540 (or 66538 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21000412 is about 4582.6206476207. The cubic root of 21000412 is about 275.8942218751.

Adding to 21000412 its reverse (21400012), we get a palindrome (42400424).

It can be divided in two parts, 21000 and 412, that added together give a palindrome (21412).

The spelling of 21000412 in words is "twenty-one million, four hundred twelve", and thus it is an aban number.