21691703667 has 16 divisors (see below), whose sum is σ = 29263489920. Its totient is φ = 14290966272.

The previous prime is 21691703603. The next prime is 21691703669. The reversal of 21691703667 is 76630719612.

It is a happy number.

It is not a de Polignac number, because 21691703667 - 2⁶ = 21691703603 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21691703669) 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 in 15 ways as a sum of consecutive naturals, for example, 144184 + ... + 253322.

It is an arithmetic number, because the mean of its divisors is an integer number (1828968120).

Almost surely, 2^21691703667 is an apocalyptic number.

21691703667 is a deficient number, since it is larger than the sum of its proper divisors (7571786253).

21691703667 is a wasteful number, since it uses less digits than its factorization.

21691703667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109922.

The product of its (nonzero) digits is 571536, while the sum is 48.

The spelling of 21691703667 in words is "twenty-one billion, six hundred ninety-one million, seven hundred three thousand, six hundred sixty-seven".