21316605304523 has 2 divisors, whose sum is σ = 21316605304524. Its totient is φ = 21316605304522.

The previous prime is 21316605304517. The next prime is 21316605304543. The reversal of 21316605304523 is 32540350661312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21316605304523 - 2¹⁶ = 21316605238987 is a prime.

It is not a weakly prime, because it can be changed into another prime (21316605304543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10658302652261 + 10658302652262.

It is an arithmetic number, because the mean of its divisors is an integer number (10658302652262).

Almost surely, 2^{21316605304523} is an apocalyptic number.

21316605304523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21316605304523 is an equidigital number, since it uses as much as digits as its factorization.

21316605304523 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 388800, while the sum is 41.

Adding to 21316605304523 its reverse (32540350661312), we get a palindrome (53856955965835).

The spelling of 21316605304523 in words is "twenty-one trillion, three hundred sixteen billion, six hundred five million, three hundred four thousand, five hundred twenty-three".