21404024243 has 4 divisors (see below), whose sum is σ = 24461742000. Its totient is φ = 18346306488.

The previous prime is 21404024231. The next prime is 21404024261. The reversal of 21404024243 is 34242040412.

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 21404024243 - 2¹⁶ = 21403958707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21404024263) 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, 1528858868 + ... + 1528858881.

It is an arithmetic number, because the mean of its divisors is an integer number (6115435500).

Almost surely, 2^21404024243 is an apocalyptic number.

21404024243 is a deficient number, since it is larger than the sum of its proper divisors (3057717757).

21404024243 is an equidigital number, since it uses as much as digits as its factorization.

21404024243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3057717756.

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 21404024243 its reverse (34242040412), we get a palindrome (55646064655).

The spelling of 21404024243 in words is "twenty-one billion, four hundred four million, twenty-four thousand, two hundred forty-three".