21531204523267 has 2 divisors, whose sum is σ = 21531204523268. Its totient is φ = 21531204523266.

The previous prime is 21531204523261. The next prime is 21531204523417. The reversal of 21531204523267 is 76232540213512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21531204523267 - 2¹¹ = 21531204521219 is a prime.

It is not a weakly prime, because it can be changed into another prime (21531204523261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10765602261633 + 10765602261634.

It is an arithmetic number, because the mean of its divisors is an integer number (10765602261634).

Almost surely, 2^{21531204523267} is an apocalyptic number.

21531204523267 is a deficient number, since it is larger than the sum of its proper divisors (1).

21531204523267 is an equidigital number, since it uses as much as digits as its factorization.

21531204523267 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 604800, while the sum is 43.

Adding to 21531204523267 its reverse (76232540213512), we get a palindrome (97763744736779).

The spelling of 21531204523267 in words is "twenty-one trillion, five hundred thirty-one billion, two hundred four million, five hundred twenty-three thousand, two hundred sixty-seven".