21697821696 has 88 divisors (see below), whose sum is σ = 60347263104. Its totient is φ = 6918123520.

The previous prime is 21697821653. The next prime is 21697821697. The reversal of 21697821696 is 69612879612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21697821697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82890 + ... + 224201.

Almost surely, 2^21697821696 is an apocalyptic number.

It is an amenable number.

21697821696 is an abundant number, since it is smaller than the sum of its proper divisors (38649441408).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21697821696 is a wasteful number, since it uses less digits than its factorization.

21697821696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307137 (or 307119 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 57.

The spelling of 21697821696 in words is "twenty-one billion, six hundred ninety-seven million, eight hundred twenty-one thousand, six hundred ninety-six".