21068021067 has 4 divisors (see below), whose sum is σ = 28090694760. Its totient is φ = 14045347376.

The previous prime is 21068021059. The next prime is 21068021099. The reversal of 21068021067 is 76012086012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21068021067 - 2³ = 21068021059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21068021267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3511336842 + ... + 3511336847.

It is an arithmetic number, because the mean of its divisors is an integer number (7022673690).

Almost surely, 2^21068021067 is an apocalyptic number.

21068021067 is a deficient number, since it is larger than the sum of its proper divisors (7022673693).

21068021067 is an equidigital number, since it uses as much as digits as its factorization.

21068021067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7022673692.

The product of its (nonzero) digits is 8064, while the sum is 33.

The spelling of 21068021067 in words is "twenty-one billion, sixty-eight million, twenty-one thousand, sixty-seven".