21111953012287 has 2 divisors, whose sum is σ = 21111953012288. Its totient is φ = 21111953012286.

The previous prime is 21111953012279. The next prime is 21111953012317. The reversal of 21111953012287 is 78221035911112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21111953012287 - 2³ = 21111953012279 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111953010287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555976506143 + 10555976506144.

It is an arithmetic number, because the mean of its divisors is an integer number (10555976506144).

Almost surely, 2^{21111953012287} is an apocalyptic number.

21111953012287 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111953012287 is an equidigital number, since it uses as much as digits as its factorization.

21111953012287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 43.

Adding to 21111953012287 its reverse (78221035911112), we get a palindrome (99332988923399).

The spelling of 21111953012287 in words is "twenty-one trillion, one hundred eleven billion, nine hundred fifty-three million, twelve thousand, two hundred eighty-seven".