21256215004067 has 2 divisors, whose sum is σ = 21256215004068. Its totient is φ = 21256215004066.

The previous prime is 21256215004019. The next prime is 21256215004121. The reversal of 21256215004067 is 76040051265212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21256215004067 - 2²² = 21256210809763 is a prime.

It is not a weakly prime, because it can be changed into another prime (21256215004667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10628107502033 + 10628107502034.

It is an arithmetic number, because the mean of its divisors is an integer number (10628107502034).

Almost surely, 2^{21256215004067} is an apocalyptic number.

21256215004067 is a deficient number, since it is larger than the sum of its proper divisors (1).

21256215004067 is an equidigital number, since it uses as much as digits as its factorization.

21256215004067 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 201600, while the sum is 41.

Adding to 21256215004067 its reverse (76040051265212), we get a palindrome (97296266269279).

The spelling of 21256215004067 in words is "twenty-one trillion, two hundred fifty-six billion, two hundred fifteen million, four thousand, sixty-seven".