21344423401 has 4 divisors (see below), whose sum is σ = 24393626752. Its totient is φ = 18295220052.

The previous prime is 21344423339. The next prime is 21344423411. The reversal of 21344423401 is 10432444312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21344423401 - 2⁹ = 21344422889 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21344423401.

It is not an unprimeable number, because it can be changed into a prime (21344423411) 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, 1524601665 + ... + 1524601678.

It is an arithmetic number, because the mean of its divisors is an integer number (6098406688).

Almost surely, 2^21344423401 is an apocalyptic number.

It is an amenable number.

21344423401 is a deficient number, since it is larger than the sum of its proper divisors (3049203351).

21344423401 is an equidigital number, since it uses as much as digits as its factorization.

21344423401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3049203350.

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 21344423401 its reverse (10432444312), we get a palindrome (31776867713).

The spelling of 21344423401 in words is "twenty-one billion, three hundred forty-four million, four hundred twenty-three thousand, four hundred one".