21440021034400 has 72 divisors (see below), whose sum is σ = 52343374184640. Its totient is φ = 8575529506560.

The previous prime is 21440021034361. The next prime is 21440021034427. The reversal of 21440021034400 is 443012004412.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13762371 + ... + 15240829.

It is an arithmetic number, because the mean of its divisors is an integer number (726991308120).

Almost surely, 2^{21440021034400} is an apocalyptic number.

21440021034400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21440021034400 is an abundant number, since it is smaller than the sum of its proper divisors (30903353150240).

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

21440021034400 is a wasteful number, since it uses less digits than its factorization.

21440021034400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1496606 (or 1496593 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21440021034400 its reverse (443012004412), we get a palindrome (21883033038812).

The spelling of 21440021034400 in words is "twenty-one trillion, four hundred forty billion, twenty-one million, thirty-four thousand, four hundred".