21413541 has 4 divisors (see below), whose sum is σ = 28551392. Its totient is φ = 14275692.

The previous prime is 21413533. The next prime is 21413549. The reversal of 21413541 is 14531412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (21413533) and next prime (21413549).

It is not a de Polignac number, because 21413541 - 2³ = 21413533 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 (21413549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3568921 + ... + 3568926.

It is an arithmetic number, because the mean of its divisors is an integer number (7137848).

Almost surely, 2^21413541 is an apocalyptic number.

It is an amenable number.

21413541 is a deficient number, since it is larger than the sum of its proper divisors (7137851).

21413541 is an equidigital number, since it uses as much as digits as its factorization.

21413541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7137850.

The product of its digits is 480, while the sum is 21.

The square root of 21413541 is about 4627.4767422430. The cubic root of 21413541 is about 277.6916556066.

Adding to 21413541 its reverse (14531412), we get a palindrome (35944953).

The spelling of 21413541 in words is "twenty-one million, four hundred thirteen thousand, five hundred forty-one".