21010440443 has 4 divisors (see below), whose sum is σ = 21043738128. Its totient is φ = 20977142760.

The previous prime is 21010440427. The next prime is 21010440457. The reversal of 21010440443 is 34404401012.

It is a happy number.

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 21010440443 - 2⁴ = 21010440427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010440643) 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, 16647896 + ... + 16649157.

It is an arithmetic number, because the mean of its divisors is an integer number (5260934532).

Almost surely, 2^21010440443 is an apocalyptic number.

21010440443 is a deficient number, since it is larger than the sum of its proper divisors (33297685).

21010440443 is an equidigital number, since it uses as much as digits as its factorization.

21010440443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33297684.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21010440443 its reverse (34404401012), we get a palindrome (55414841455).

The spelling of 21010440443 in words is "twenty-one billion, ten million, four hundred forty thousand, four hundred forty-three".