21644034103 has 4 divisors (see below), whose sum is σ = 22585079088. Its totient is φ = 20702989120.

The previous prime is 21644034101. The next prime is 21644034107. The reversal of 21644034103 is 30143044612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21644034103 - 2¹ = 21644034101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21644034101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 470522458 + ... + 470522503.

It is an arithmetic number, because the mean of its divisors is an integer number (5646269772).

Almost surely, 2^21644034103 is an apocalyptic number.

21644034103 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21644034103 is a deficient number, since it is larger than the sum of its proper divisors (941044985).

21644034103 is an equidigital number, since it uses as much as digits as its factorization.

21644034103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 941044984.

The product of its (nonzero) digits is 6912, while the sum is 28.

Adding to 21644034103 its reverse (30143044612), we get a palindrome (51787078715).

The spelling of 21644034103 in words is "twenty-one billion, six hundred forty-four million, thirty-four thousand, one hundred three".