21214081 has 8 divisors (see below), whose sum is σ = 24274944. Its totient is φ = 18160800.

The previous prime is 21214049. The next prime is 21214087. The reversal of 21214081 is 18041212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21214081 - 2⁵ = 21214049 is a prime.

It is a super-2 number, since 2×21214081² = 900074465349122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21214087) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 6741 + ... + 9373.

It is an arithmetic number, because the mean of its divisors is an integer number (3034368).

Almost surely, 2^21214081 is an apocalyptic number.

It is an amenable number.

21214081 is a deficient number, since it is larger than the sum of its proper divisors (3060863).

21214081 is a wasteful number, since it uses less digits than its factorization.

21214081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3791.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 21214081 is about 4605.8746183543. The cubic root of 21214081 is about 276.8267628753.

Adding to 21214081 its reverse (18041212), we get a palindrome (39255293).

The spelling of 21214081 in words is "twenty-one million, two hundred fourteen thousand, eighty-one".