21203413 has 16 divisors (see below), whose sum is σ = 26536320. Its totient is φ = 16459200.

The previous prime is 21203407. The next prime is 21203419. The reversal of 21203413 is 31430212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21203407) and next prime (21203419).

It is a cyclic number.

It is not a de Polignac number, because 21203413 - 2⁹ = 21202901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203419) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38923 + ... + 39463.

It is an arithmetic number, because the mean of its divisors is an integer number (1658520).

Almost surely, 2^21203413 is an apocalyptic number.

It is an amenable number.

21203413 is a deficient number, since it is larger than the sum of its proper divisors (5332907).

21203413 is a wasteful number, since it uses less digits than its factorization.

21203413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1068.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21203413 is about 4604.7163864890. The cubic root of 21203413 is about 276.7803521435.

Adding to 21203413 its reverse (31430212), we get a palindrome (52633625).

The spelling of 21203413 in words is "twenty-one million, two hundred three thousand, four hundred thirteen".