21325440423 has 16 divisors (see below), whose sum is σ = 33544165376. Its totient is φ = 11792869920.

The previous prime is 21325440421. The next prime is 21325440439. The reversal of 21325440423 is 32404452312.

It is not a de Polignac number, because 21325440423 - 2¹ = 21325440421 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 (21325440421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16378336 + ... + 16379637.

It is an arithmetic number, because the mean of its divisors is an integer number (2096510336).

Almost surely, 2^21325440423 is an apocalyptic number.

21325440423 is a deficient number, since it is larger than the sum of its proper divisors (12218724953).

21325440423 is a wasteful number, since it uses less digits than its factorization.

21325440423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32758014.

The product of its (nonzero) digits is 23040, while the sum is 30.

Adding to 21325440423 its reverse (32404452312), we get a palindrome (53729892735).

The spelling of 21325440423 in words is "twenty-one billion, three hundred twenty-five million, four hundred forty thousand, four hundred twenty-three".