21331634687 has 8 divisors (see below), whose sum is σ = 23367436752. Its totient is φ = 19311926400.

The previous prime is 21331634659. The next prime is 21331634707. The reversal of 21331634687 is 78643613312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21331634687 - 2¹² = 21331630591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331634627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4020668 + ... + 4025969.

It is an arithmetic number, because the mean of its divisors is an integer number (2920929594).

Almost surely, 2^21331634687 is an apocalyptic number.

21331634687 is a deficient number, since it is larger than the sum of its proper divisors (2035802065).

21331634687 is a wasteful number, since it uses less digits than its factorization.

21331634687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8046889.

The product of its digits is 435456, while the sum is 44.

The spelling of 21331634687 in words is "twenty-one billion, three hundred thirty-one million, six hundred thirty-four thousand, six hundred eighty-seven".