21867800687 has 4 divisors (see below), whose sum is σ = 22014564600. Its totient is φ = 21721036776.

The previous prime is 21867800681. The next prime is 21867800719. The reversal of 21867800687 is 78600876812.

It is a happy number.

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 21867800687 - 2⁶ = 21867800623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21867800681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73381733 + ... + 73382030.

It is an arithmetic number, because the mean of its divisors is an integer number (5503641150).

Almost surely, 2^21867800687 is an apocalyptic number.

21867800687 is a deficient number, since it is larger than the sum of its proper divisors (146763913).

21867800687 is a wasteful number, since it uses less digits than its factorization.

21867800687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146763912.

The product of its (nonzero) digits is 1806336, while the sum is 53.

The spelling of 21867800687 in words is "twenty-one billion, eight hundred sixty-seven million, eight hundred thousand, six hundred eighty-seven".