21384853671 has 4 divisors (see below), whose sum is σ = 28513138232. Its totient is φ = 14256569112.

The previous prime is 21384853667. The next prime is 21384853687. The reversal of 21384853671 is 17635848312.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21384853671 - 2² = 21384853667 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21384853671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21384853621) 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, 3564142276 + ... + 3564142281.

It is an arithmetic number, because the mean of its divisors is an integer number (7128284558).

Almost surely, 2^21384853671 is an apocalyptic number.

21384853671 is a deficient number, since it is larger than the sum of its proper divisors (7128284561).

21384853671 is an equidigital number, since it uses as much as digits as its factorization.

21384853671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7128284560.

The product of its digits is 967680, while the sum is 48.

The spelling of 21384853671 in words is "twenty-one billion, three hundred eighty-four million, eight hundred fifty-three thousand, six hundred seventy-one".