21421412 has 12 divisors (see below), whose sum is σ = 38001516. Its totient is φ = 10563840.

The previous prime is 21421399. The next prime is 21421427. The reversal of 21421412 is 21412412.

It can be written as a sum of positive squares in 2 ways, for example, as 15241216 + 6180196 = 3904^2 + 2486^2 .

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36389 + ... + 36972.

It is an arithmetic number, because the mean of its divisors is an integer number (3166793).

Almost surely, 2^21421412 is an apocalyptic number.

It is an amenable number.

21421412 is a deficient number, since it is larger than the sum of its proper divisors (16580104).

21421412 is a wasteful number, since it uses less digits than its factorization.

21421412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73438 (or 73436 counting only the distinct ones).

The product of its digits is 128, while the sum is 17.

The square root of 21421412 is about 4628.3271275916. The cubic root of 21421412 is about 277.7256752530.

Adding to 21421412 its reverse (21412412), we get a palindrome (42833824).

The spelling of 21421412 in words is "twenty-one million, four hundred twenty-one thousand, four hundred twelve".