21411021 has 8 divisors (see below), whose sum is σ = 28815264. Its totient is φ = 14140400.

The previous prime is 21411017. The next prime is 21411023. The reversal of 21411021 is 12011412.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21411021 - 2² = 21411017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21410988 and 21411006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21411023) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 33030 + ... + 33671.

It is an arithmetic number, because the mean of its divisors is an integer number (3601908).

Almost surely, 2^21411021 is an apocalyptic number.

It is an amenable number.

21411021 is a deficient number, since it is larger than the sum of its proper divisors (7404243).

21411021 is a wasteful number, since it uses less digits than its factorization.

21411021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66811.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 21411021 is about 4627.2044476120. The cubic root of 21411021 is about 277.6807620257.

Adding to 21411021 its reverse (12011412), we get a palindrome (33422433).

The spelling of 21411021 in words is "twenty-one million, four hundred eleven thousand, twenty-one".