21519684205 has 8 divisors (see below), whose sum is σ = 25828669152. Its totient is φ = 17212381968.

The previous prime is 21519684103. The next prime is 21519684211. The reversal of 21519684205 is 50248691512.

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

It is a cyclic number.

It is not a de Polignac number, because 21519684205 - 2⁷ = 21519684077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 392367 + ... + 443836.

It is an arithmetic number, because the mean of its divisors is an integer number (3228583644).

Almost surely, 2^21519684205 is an apocalyptic number.

It is an amenable number.

21519684205 is a deficient number, since it is larger than the sum of its proper divisors (4308984947).

21519684205 is an equidigital number, since it uses as much as digits as its factorization.

21519684205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 841355.

The product of its (nonzero) digits is 172800, while the sum is 43.

The spelling of 21519684205 in words is "twenty-one billion, five hundred nineteen million, six hundred eighty-four thousand, two hundred five".