21667357193 has 2 divisors, whose sum is σ = 21667357194. Its totient is φ = 21667357192.

The previous prime is 21667357181. The next prime is 21667357219. The reversal of 21667357193 is 39175376612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21423591424 + 243765769 = 146368^2 + 15613^2 .

It is a cyclic number.

It is not a de Polignac number, because 21667357193 - 2⁸ = 21667356937 is a prime.

It is not a weakly prime, because it can be changed into another prime (21667353193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10833678596 + 10833678597.

It is an arithmetic number, because the mean of its divisors is an integer number (10833678597).

Almost surely, 2^21667357193 is an apocalyptic number.

It is an amenable number.

21667357193 is a deficient number, since it is larger than the sum of its proper divisors (1).

21667357193 is an equidigital number, since it uses as much as digits as its factorization.

21667357193 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1428840, while the sum is 50.

The spelling of 21667357193 in words is "twenty-one billion, six hundred sixty-seven million, three hundred fifty-seven thousand, one hundred ninety-three".