21679970671 has 2 divisors, whose sum is σ = 21679970672. Its totient is φ = 21679970670.

The previous prime is 21679970651. The next prime is 21679970677. The reversal of 21679970671 is 17607997612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21679970671 - 2¹¹ = 21679968623 is a prime.

It is a super-2 number, since 2×21679970671² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21679970677) 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, 10839985335 + 10839985336.

It is an arithmetic number, because the mean of its divisors is an integer number (10839985336).

Almost surely, 2^21679970671 is an apocalyptic number.

21679970671 is a deficient number, since it is larger than the sum of its proper divisors (1).

21679970671 is an equidigital number, since it uses as much as digits as its factorization.

21679970671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2000376, while the sum is 55.

The spelling of 21679970671 in words is "twenty-one billion, six hundred seventy-nine million, nine hundred seventy thousand, six hundred seventy-one".