21202445 has 16 divisors (see below), whose sum is σ = 27855360. Its totient is φ = 15364800.

The previous prime is 21202429. The next prime is 21202459. The reversal of 21202445 is 54420212.

It is a happy number.

It is not a de Polignac number, because 21202445 - 2⁴ = 21202429 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20900 + ... + 21890.

It is an arithmetic number, because the mean of its divisors is an integer number (1740960).

Almost surely, 2^21202445 is an apocalyptic number.

It is an amenable number.

21202445 is a deficient number, since it is larger than the sum of its proper divisors (6652915).

21202445 is a wasteful number, since it uses less digits than its factorization.

21202445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1396.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 21202445 is about 4604.6112756670. The cubic root of 21202445 is about 276.7761401257.

Adding to 21202445 its reverse (54420212), we get a palindrome (75622657).

The spelling of 21202445 in words is "twenty-one million, two hundred two thousand, four hundred forty-five".