21866118047 has 2 divisors, whose sum is σ = 21866118048. Its totient is φ = 21866118046.

The previous prime is 21866118019. The next prime is 21866118077. The reversal of 21866118047 is 74081166812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21866118047 - 2¹⁸ = 21865855903 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21866117989 and 21866118007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21866118077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10933059023 + 10933059024.

It is an arithmetic number, because the mean of its divisors is an integer number (10933059024).

Almost surely, 2^21866118047 is an apocalyptic number.

21866118047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21866118047 is an equidigital number, since it uses as much as digits as its factorization.

21866118047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 129024, while the sum is 44.

The spelling of 21866118047 in words is "twenty-one billion, eight hundred sixty-six million, one hundred eighteen thousand, forty-seven".