21424201 has 4 divisors (see below), whose sum is σ = 22355712. Its totient is φ = 20492692.

The previous prime is 21424189. The next prime is 21424213. The reversal of 21424201 is 10242412.

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 (21424189) and next prime (21424213).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21424201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21424241) 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 3 ways as a sum of consecutive naturals, for example, 465721 + ... + 465766.

It is an arithmetic number, because the mean of its divisors is an integer number (5588928).

Almost surely, 2^21424201 is an apocalyptic number.

It is an amenable number.

21424201 is a deficient number, since it is larger than the sum of its proper divisors (931511).

21424201 is an equidigital number, since it uses as much as digits as its factorization.

21424201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931510.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21424201 is about 4628.6284145522. The cubic root of 21424201 is about 277.7377277310.

Adding to 21424201 its reverse (10242412), we get a palindrome (31666613).

The spelling of 21424201 in words is "twenty-one million, four hundred twenty-four thousand, two hundred one".