21510052211387 has 2 divisors, whose sum is σ = 21510052211388. Its totient is φ = 21510052211386.

The previous prime is 21510052211269. The next prime is 21510052211399. The reversal of 21510052211387 is 78311225001512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21510052211387 - 2¹⁰ = 21510052210363 is a prime.

It is a super-2 number, since 2×21510052211387² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21510052211387.

It is not a weakly prime, because it can be changed into another prime (21510052261387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10755026105693 + 10755026105694.

It is an arithmetic number, because the mean of its divisors is an integer number (10755026105694).

Almost surely, 2^{21510052211387} is an apocalyptic number.

21510052211387 is a deficient number, since it is larger than the sum of its proper divisors (1).

21510052211387 is an equidigital number, since it uses as much as digits as its factorization.

21510052211387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 33600, while the sum is 38.

Adding to 21510052211387 its reverse (78311225001512), we get a palindrome (99821277212899).

The spelling of 21510052211387 in words is "twenty-one trillion, five hundred ten billion, fifty-two million, two hundred eleven thousand, three hundred eighty-seven".