21531204523211 has 2 divisors, whose sum is σ = 21531204523212. Its totient is φ = 21531204523210.

The previous prime is 21531204523183. The next prime is 21531204523219. The reversal of 21531204523211 is 11232540213512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21531204523211 - 2¹⁰ = 21531204522187 is a prime.

It is not a weakly prime, because it can be changed into another prime (21531204523219) 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 as a sum of consecutive naturals, namely, 10765602261605 + 10765602261606.

It is an arithmetic number, because the mean of its divisors is an integer number (10765602261606).

Almost surely, 2^{21531204523211} is an apocalyptic number.

21531204523211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21531204523211 is an equidigital number, since it uses as much as digits as its factorization.

21531204523211 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14400, while the sum is 32.

Adding to 21531204523211 its reverse (11232540213512), we get a palindrome (32763744736723).

The spelling of 21531204523211 in words is "twenty-one trillion, five hundred thirty-one billion, two hundred four million, five hundred twenty-three thousand, two hundred eleven".