21665377267 has 2 divisors, whose sum is σ = 21665377268. Its totient is φ = 21665377266.

The previous prime is 21665377249. The next prime is 21665377273. The reversal of 21665377267 is 76277356612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21665377267 - 2²⁷ = 21531159539 is a prime.

It is a super-3 number, since 3×21665377267³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21665377567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10832688633 + 10832688634.

It is an arithmetic number, because the mean of its divisors is an integer number (10832688634).

Almost surely, 2^21665377267 is an apocalyptic number.

21665377267 is a deficient number, since it is larger than the sum of its proper divisors (1).

21665377267 is an equidigital number, since it uses as much as digits as its factorization.

21665377267 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4445280, while the sum is 52.

The spelling of 21665377267 in words is "twenty-one billion, six hundred sixty-five million, three hundred seventy-seven thousand, two hundred sixty-seven".