21159627640 has 16 divisors (see below), whose sum is σ = 47609162280. Its totient is φ = 8463851040.

The previous prime is 21159627631. The next prime is 21159627641. The reversal of 21159627640 is 4672695112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21159627641) 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, 264495306 + ... + 264495385.

Almost surely, 2^21159627640 is an apocalyptic number.

21159627640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21159627640 is an abundant number, since it is smaller than the sum of its proper divisors (26449534640).

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

21159627640 is a wasteful number, since it uses less digits than its factorization.

21159627640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528990702 (or 528990698 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 43.

The spelling of 21159627640 in words is "twenty-one billion, one hundred fifty-nine million, six hundred twenty-seven thousand, six hundred forty".