21500502323021 has 4 divisors (see below), whose sum is σ = 22435306771872. Its totient is φ = 20565697874172.

The previous prime is 21500502323011. The next prime is 21500502323081. The reversal of 21500502323021 is 12032320500512.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 21500502323021 - 2¹⁴ = 21500502306637 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 (21500502323011) 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, 467402224391 + ... + 467402224436.

It is an arithmetic number, because the mean of its divisors is an integer number (5608826692968).

Almost surely, 2^{21500502323021} is an apocalyptic number.

It is an amenable number.

21500502323021 is a deficient number, since it is larger than the sum of its proper divisors (934804448851).

21500502323021 is an equidigital number, since it uses as much as digits as its factorization.

21500502323021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 934804448850.

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21500502323021 its reverse (12032320500512), we get a palindrome (33532822823533).

The spelling of 21500502323021 in words is "twenty-one trillion, five hundred billion, five hundred two million, three hundred twenty-three thousand, twenty-one".