21200343444 has 36 divisors (see below), whose sum is σ = 61245437344. Its totient is φ = 6057240912.

The previous prime is 21200343443. The next prime is 21200343481. The reversal of 21200343444 is 44434300212.

It is a happy number.

21200343444 is a `hidden beast` number, since 21 + 200 + 3 + 434 + 4 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21200343444² (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 (21200343443) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42063922 + ... + 42064425.

Almost surely, 2^21200343444 is an apocalyptic number.

It is an amenable number.

21200343444 is an abundant number, since it is smaller than the sum of its proper divisors (40045093900).

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

21200343444 is a wasteful number, since it uses less digits than its factorization.

21200343444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84128364 (or 84128359 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 21200343444 its reverse (44434300212), we get a palindrome (65634643656).

The spelling of 21200343444 in words is "twenty-one billion, two hundred million, three hundred forty-three thousand, four hundred forty-four".