21202447 has 12 divisors (see below), whose sum is σ = 24909456. Its totient is φ = 17992800.

The previous prime is 21202429. The next prime is 21202459. The reversal of 21202447 is 74420212.

It is a happy number.

It is not a de Polignac number, because 21202447 - 2¹⁵ = 21169679 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 (21202427) 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 11 ways as a sum of consecutive naturals, for example, 2947 + ... + 7147.

It is an arithmetic number, because the mean of its divisors is an integer number (2075788).

Almost surely, 2^21202447 is an apocalyptic number.

21202447 is a deficient number, since it is larger than the sum of its proper divisors (3707009).

21202447 is a wasteful number, since it uses less digits than its factorization.

21202447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4318 (or 4311 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 21202447 is about 4604.6114928406. The cubic root of 21202447 is about 276.7761488283.

Adding to 21202447 its reverse (74420212), we get a palindrome (95622659).

The spelling of 21202447 in words is "twenty-one million, two hundred two thousand, four hundred forty-seven".