21320023541 has 8 divisors (see below), whose sum is σ = 21666003864. Its totient is φ = 20975500800.

The previous prime is 21320023531. The next prime is 21320023547. The reversal of 21320023541 is 14532002312.

It can be written as a sum of positive squares in 4 ways, for example, as 14073076900 + 7246946641 = 118630^2 + 85129^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21320023541 - 2¹⁴ = 21320007157 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 (21320023547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 334886 + ... + 393431.

It is an arithmetic number, because the mean of its divisors is an integer number (2708250483).

Almost surely, 2^21320023541 is an apocalyptic number.

It is an amenable number.

21320023541 is a deficient number, since it is larger than the sum of its proper divisors (345980323).

21320023541 is an equidigital number, since it uses as much as digits as its factorization.

21320023541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 728791.

The product of its (nonzero) digits is 1440, while the sum is 23.

Adding to 21320023541 its reverse (14532002312), we get a palindrome (35852025853).

The spelling of 21320023541 in words is "twenty-one billion, three hundred twenty million, twenty-three thousand, five hundred forty-one".