21444104400 has 60 divisors (see below), whose sum is σ = 68692618272. Its totient is φ = 5718427520.

The previous prime is 21444104359. The next prime is 21444104401. The reversal of 21444104400 is 440144412.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×21444104400² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444104401) 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, 8933844 + ... + 8936243.

Almost surely, 2^21444104400 is an apocalyptic number.

21444104400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21444104400 is an abundant number, since it is smaller than the sum of its proper divisors (47248513872).

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

21444104400 is a wasteful number, since it uses less digits than its factorization.

21444104400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17870108 (or 17870097 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 24.

Adding to 21444104400 its reverse (440144412), we get a palindrome (21884248812).

The spelling of 21444104400 in words is "twenty-one billion, four hundred forty-four million, one hundred four thousand, four hundred".