21325434451 has 4 divisors (see below), whose sum is σ = 21325873032. Its totient is φ = 21324995872.

The previous prime is 21325434439. The next prime is 21325434463. The reversal of 21325434451 is 15443452312.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21325434439) and next prime (21325434463).

It is a cyclic number.

It is not a de Polignac number, because 21325434451 - 2²³ = 21317045843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21325434421) 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, 135745 + ... + 247138.

It is an arithmetic number, because the mean of its divisors is an integer number (5331468258).

Almost surely, 2^21325434451 is an apocalyptic number.

21325434451 is a deficient number, since it is larger than the sum of its proper divisors (438581).

21325434451 is an equidigital number, since it uses as much as digits as its factorization.

21325434451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438580.

The product of its digits is 57600, while the sum is 34.

Adding to 21325434451 its reverse (15443452312), we get a palindrome (36768886763).

The spelling of 21325434451 in words is "twenty-one billion, three hundred twenty-five million, four hundred thirty-four thousand, four hundred fifty-one".