21671681673079 has 2 divisors, whose sum is σ = 21671681673080. Its totient is φ = 21671681673078.

The previous prime is 21671681673067. The next prime is 21671681673097. The reversal of 21671681673079 is 97037618617612.

Together with next prime (21671681673097) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21671681673079 - 2⁷ = 21671681672951 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21671681673079.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21671681673029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10835840836539 + 10835840836540.

It is an arithmetic number, because the mean of its divisors is an integer number (10835840836540).

Almost surely, 2^{21671681673079} is an apocalyptic number.

21671681673079 is a deficient number, since it is larger than the sum of its proper divisors (1).

21671681673079 is an equidigital number, since it uses as much as digits as its factorization.

21671681673079 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32006016, while the sum is 64.

The spelling of 21671681673079 in words is "twenty-one trillion, six hundred seventy-one billion, six hundred eighty-one million, six hundred seventy-three thousand, seventy-nine".