21000413 has 8 divisors (see below), whose sum is σ = 24359232. Its totient is φ = 17731296.

The previous prime is 21000407. The next prime is 21000433. The reversal of 21000413 is 31400012.

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 21000413 - 2⁸ = 21000157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000394 and 21000403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000433) 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, 21920 + ... + 22857.

It is an arithmetic number, because the mean of its divisors is an integer number (3044904).

Almost surely, 2^21000413 is an apocalyptic number.

It is an amenable number.

21000413 is a deficient number, since it is larger than the sum of its proper divisors (3358819).

21000413 is an equidigital number, since it uses as much as digits as its factorization.

21000413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44851.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21000413 is about 4582.6207567286. The cubic root of 21000413 is about 275.8942262543.

Adding to 21000413 its reverse (31400012), we get a palindrome (52400425).

The spelling of 21000413 in words is "twenty-one million, four hundred thirteen", and thus it is an aban number.