21704784213 has 8 divisors (see below), whose sum is σ = 33073956928. Its totient is φ = 12402733824.

The previous prime is 21704784191. The next prime is 21704784239. The reversal of 21704784213 is 31248740712.

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

It is not a de Polignac number, because 21704784213 - 2¹⁸ = 21704522069 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 (21704784293) 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, 516780556 + ... + 516780597.

It is an arithmetic number, because the mean of its divisors is an integer number (4134244616).

Almost surely, 2^21704784213 is an apocalyptic number.

It is an amenable number.

21704784213 is a deficient number, since it is larger than the sum of its proper divisors (11369172715).

21704784213 is a wasteful number, since it uses less digits than its factorization.

21704784213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1033561163.

The product of its (nonzero) digits is 75264, while the sum is 39.

The spelling of 21704784213 in words is "twenty-one billion, seven hundred four million, seven hundred eighty-four thousand, two hundred thirteen".