21330412 has 24 divisors (see below), whose sum is σ = 37990400. Its totient is φ = 10478160.

The previous prime is 21330403. The next prime is 21330443. The reversal of 21330412 is 21403312.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100987 + ... + 101197.

Almost surely, 2^21330412 is an apocalyptic number.

It is an amenable number.

21330412 is a deficient number, since it is larger than the sum of its proper divisors (16659988).

21330412 is a wasteful number, since it uses less digits than its factorization.

21330412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541 (or 539 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21330412 is about 4618.4858990799. The cubic root of 21330412 is about 277.3318495411.

Adding to 21330412 its reverse (21403312), we get a palindrome (42733724).

Subtracting 21330412 from its reverse (21403312), we obtain a square (72900 = 270²).

It can be divided in two parts, 213 and 30412, that added together give a square (30625 = 175²).

The spelling of 21330412 in words is "twenty-one million, three hundred thirty thousand, four hundred twelve".