21320243541 has 48 divisors (see below), whose sum is σ = 33419692800. Its totient is φ = 13091505792.

The previous prime is 21320243513. The next prime is 21320243551. The reversal of 21320243541 is 14534202312.

21320243541 is a `hidden beast` number, since 21 + 3 + 202 + 435 + 4 + 1 = 666.

It is not a de Polignac number, because 21320243541 - 2⁹ = 21320243029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320243551) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2073070 + ... + 2083328.

It is an arithmetic number, because the mean of its divisors is an integer number (696243600).

Almost surely, 2^21320243541 is an apocalyptic number.

It is an amenable number.

21320243541 is a deficient number, since it is larger than the sum of its proper divisors (12099449259).

21320243541 is a wasteful number, since it uses less digits than its factorization.

21320243541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10363 (or 10326 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 21320243541 its reverse (14534202312), we get a palindrome (35854445853).

The spelling of 21320243541 in words is "twenty-one billion, three hundred twenty million, two hundred forty-three thousand, five hundred forty-one".