21871683867 has 16 divisors (see below), whose sum is σ = 32673180672. Its totient is φ = 12897306720.

The previous prime is 21871683857. The next prime is 21871683887. The reversal of 21871683867 is 76838617812.

It is not a de Polignac number, because 21871683867 - 2⁴ = 21871683851 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21871683857) 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 15 ways as a sum of consecutive naturals, for example, 8955243 + ... + 8957684.

It is an arithmetic number, because the mean of its divisors is an integer number (2042073792).

Almost surely, 2^21871683867 is an apocalyptic number.

21871683867 is a deficient number, since it is larger than the sum of its proper divisors (10801496805).

21871683867 is a wasteful number, since it uses less digits than its factorization.

21871683867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17912978.

The product of its digits is 5419008, while the sum is 57.

The spelling of 21871683867 in words is "twenty-one billion, eight hundred seventy-one million, six hundred eighty-three thousand, eight hundred sixty-seven".