21200403444 has 48 divisors (see below), whose sum is σ = 54770128896. Its totient is φ = 6328476000.

The previous prime is 21200403443. The next prime is 21200403467. The reversal of 21200403444 is 44430400212.

It is a happy number.

It is a super-2 number, since 2×21200403444² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200403443) 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, 1189732 + ... + 1207419.

It is an arithmetic number, because the mean of its divisors is an integer number (1141044352).

Almost surely, 2^21200403444 is an apocalyptic number.

It is an amenable number.

21200403444 is an abundant number, since it is smaller than the sum of its proper divisors (33569725452).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21200403444 is a wasteful number, since it uses less digits than its factorization.

21200403444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2397236 (or 2397234 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 21200403444 its reverse (44430400212), we get a palindrome (65630803656).

The spelling of 21200403444 in words is "twenty-one billion, two hundred million, four hundred three thousand, four hundred forty-four".