21432320413 has 4 divisors (see below), whose sum is σ = 24494080480. Its totient is φ = 18370560348.

The previous prime is 21432320389. The next prime is 21432320491. The reversal of 21432320413 is 31402323412.

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 not a de Polignac number, because 21432320413 - 2⁹ = 21432319901 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 (21432320513) 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, 1530880023 + ... + 1530880036.

It is an arithmetic number, because the mean of its divisors is an integer number (6123520120).

Almost surely, 2^21432320413 is an apocalyptic number.

It is an amenable number.

21432320413 is a deficient number, since it is larger than the sum of its proper divisors (3061760067).

21432320413 is an equidigital number, since it uses as much as digits as its factorization.

21432320413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3061760066.

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21432320413 its reverse (31402323412), we get a palindrome (52834643825).

The spelling of 21432320413 in words is "twenty-one billion, four hundred thirty-two million, three hundred twenty thousand, four hundred thirteen".