21838668387 has 8 divisors (see below), whose sum is σ = 29795392704. Its totient is φ = 14220528168.

The previous prime is 21838668353. The next prime is 21838668403. The reversal of 21838668387 is 78386683812.

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

It is not a de Polignac number, because 21838668387 - 2¹⁰ = 21838667363 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21838668387.

It is not an unprimeable number, because it can be changed into a prime (21838668307) 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, 84645873 + ... + 84646130.

It is an arithmetic number, because the mean of its divisors is an integer number (3724424088).

Almost surely, 2^21838668387 is an apocalyptic number.

21838668387 is a deficient number, since it is larger than the sum of its proper divisors (7956724317).

21838668387 is a wasteful number, since it uses less digits than its factorization.

21838668387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169292049.

The product of its digits is 18579456, while the sum is 60.

The spelling of 21838668387 in words is "twenty-one billion, eight hundred thirty-eight million, six hundred sixty-eight thousand, three hundred eighty-seven".