21715555424267 has 2 divisors, whose sum is σ = 21715555424268. Its totient is φ = 21715555424266.

The previous prime is 21715555424239. The next prime is 21715555424333. The reversal of 21715555424267 is 76242455551712.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21715555424267 - 2¹⁸ = 21715555162123 is a prime.

It is not a weakly prime, because it can be changed into another prime (21715555424207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10857777712133 + 10857777712134.

It is an arithmetic number, because the mean of its divisors is an integer number (10857777712134).

Almost surely, 2^{21715555424267} is an apocalyptic number.

21715555424267 is a deficient number, since it is larger than the sum of its proper divisors (1).

21715555424267 is an equidigital number, since it uses as much as digits as its factorization.

21715555424267 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23520000, while the sum is 56.

The spelling of 21715555424267 in words is "twenty-one trillion, seven hundred fifteen billion, five hundred fifty-five million, four hundred twenty-four thousand, two hundred sixty-seven".