21667464089 has 2 divisors, whose sum is σ = 21667464090. Its totient is φ = 21667464088.

The previous prime is 21667464079. The next prime is 21667464097. The reversal of 21667464089 is 98046476612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16022496400 + 5644967689 = 126580^2 + 75133^2 .

It is a cyclic number.

It is not a de Polignac number, because 21667464089 - 2⁸ = 21667463833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21667464089.

It is not a weakly prime, because it can be changed into another prime (21667464079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10833732044 + 10833732045.

It is an arithmetic number, because the mean of its divisors is an integer number (10833732045).

Almost surely, 2^21667464089 is an apocalyptic number.

It is an amenable number.

21667464089 is a deficient number, since it is larger than the sum of its proper divisors (1).

21667464089 is an equidigital number, since it uses as much as digits as its factorization.

21667464089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3483648, while the sum is 53.

The spelling of 21667464089 in words is "twenty-one billion, six hundred sixty-seven million, four hundred sixty-four thousand, eighty-nine".