21766548667 has 2 divisors, whose sum is σ = 21766548668. Its totient is φ = 21766548666.

The previous prime is 21766548659. The next prime is 21766548697. The reversal of 21766548667 is 76684566712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21766548667 - 2³ = 21766548659 is a prime.

It is not a weakly prime, because it can be changed into another prime (21766548697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10883274333 + 10883274334.

It is an arithmetic number, because the mean of its divisors is an integer number (10883274334).

Almost surely, 2^21766548667 is an apocalyptic number.

21766548667 is a deficient number, since it is larger than the sum of its proper divisors (1).

21766548667 is an equidigital number, since it uses as much as digits as its factorization.

21766548667 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20321280, while the sum is 58.

The spelling of 21766548667 in words is "twenty-one billion, seven hundred sixty-six million, five hundred forty-eight thousand, six hundred sixty-seven".