21105445200 has 120 divisors (see below), whose sum is σ = 77266060608. Its totient is φ = 4824099840.

The previous prime is 21105445187. The next prime is 21105445241. The reversal of 21105445200 is 254450112.

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1247877 + ... + 1264676.

Almost surely, 2^21105445200 is an apocalyptic number.

21105445200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21105445200 is an abundant number, since it is smaller than the sum of its proper divisors (56160615408).

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

21105445200 is a wasteful number, since it uses less digits than its factorization.

21105445200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2512581 (or 2512570 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

Adding to 21105445200 its reverse (254450112), we get a palindrome (21359895312).

The spelling of 21105445200 in words is "twenty-one billion, one hundred five million, four hundred forty-five thousand, two hundred".