21516304035223 has 2 divisors, whose sum is σ = 21516304035224. Its totient is φ = 21516304035222.

The previous prime is 21516304035203. The next prime is 21516304035257. The reversal of 21516304035223 is 32253040361512.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21516304035223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21516304035203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10758152017611 + 10758152017612.

It is an arithmetic number, because the mean of its divisors is an integer number (10758152017612).

Almost surely, 2^{21516304035223} is an apocalyptic number.

21516304035223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21516304035223 is an equidigital number, since it uses as much as digits as its factorization.

21516304035223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129600, while the sum is 37.

Adding to 21516304035223 its reverse (32253040361512), we get a palindrome (53769344396735).

The spelling of 21516304035223 in words is "twenty-one trillion, five hundred sixteen billion, three hundred four million, thirty-five thousand, two hundred twenty-three".