21144320001 has 16 divisors (see below), whose sum is σ = 35799907200. Its totient is φ = 12082468464.

The previous prime is 21144319997. The next prime is 21144320011. The reversal of 21144320001 is 10002344112.

21144320001 is a `hidden beast` number, since 21 + 1 + 443 + 200 + 0 + 1 = 666.

It is not a de Polignac number, because 21144320001 - 2² = 21144319997 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21144320011) 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, 55937166 + ... + 55937543.

It is an arithmetic number, because the mean of its divisors is an integer number (2237494200).

Almost surely, 2^21144320001 is an apocalyptic number.

21144320001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21144320001 is a deficient number, since it is larger than the sum of its proper divisors (14655587199).

21144320001 is a wasteful number, since it uses less digits than its factorization.

21144320001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111874725 (or 111874719 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21144320001 its reverse (10002344112), we get a palindrome (31146664113).

The spelling of 21144320001 in words is "twenty-one billion, one hundred forty-four million, three hundred twenty thousand, one".