21021412 has 12 divisors (see below), whose sum is σ = 36833580. Its totient is φ = 10497536.

The previous prime is 21021389. The next prime is 21021419. The reversal of 21021412 is 21412012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1094116 + 19927296 = 1046^2 + 4464^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21021392 and 21021401.

It is not an unprimeable number, because it can be changed into a prime (21021419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 888 + ... + 6544.

It is an arithmetic number, because the mean of its divisors is an integer number (3069465).

Almost surely, 2^21021412 is an apocalyptic number.

It is an amenable number.

21021412 is a deficient number, since it is larger than the sum of its proper divisors (15812168).

21021412 is a wasteful number, since it uses less digits than its factorization.

21021412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6590 (or 6588 counting only the distinct ones).

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

The square root of 21021412 is about 4584.9113404732. The cubic root of 21021412 is about 275.9861541748.

Adding to 21021412 its reverse (21412012), we get a palindrome (42433424).

The spelling of 21021412 in words is "twenty-one million, twenty-one thousand, four hundred twelve".