21100004443 has 16 divisors (see below), whose sum is σ = 24656486400. Its totient is φ = 17683566336.

The previous prime is 21100004437. The next prime is 21100004459. The reversal of 21100004443 is 34440000112.

It is a cyclic number.

It is not a de Polignac number, because 21100004443 - 2⁹ = 21100003931 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21100004443.

It is not an unprimeable number, because it can be changed into a prime (21100004473) 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, 130843 + ... + 243556.

It is an arithmetic number, because the mean of its divisors is an integer number (1541030400).

Almost surely, 2^21100004443 is an apocalyptic number.

21100004443 is a deficient number, since it is larger than the sum of its proper divisors (3556481957).

21100004443 is an equidigital number, since it uses as much as digits as its factorization.

21100004443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374586.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 21100004443 its reverse (34440000112), we get a palindrome (55540004555).

The spelling of 21100004443 in words is "twenty-one billion, one hundred million, four thousand, four hundred forty-three".