21688444315 has 8 divisors (see below), whose sum is σ = 26071716528. Its totient is φ = 17320366560.

The previous prime is 21688444259. The next prime is 21688444319. The reversal of 21688444315 is 51344488612.

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

It is not a de Polignac number, because 21688444315 - 2¹¹ = 21688442267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21688444319) 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 7 ways as a sum of consecutive naturals, for example, 3795472 + ... + 3801181.

It is an arithmetic number, because the mean of its divisors is an integer number (3258964566).

Almost surely, 2^21688444315 is an apocalyptic number.

21688444315 is a deficient number, since it is larger than the sum of its proper divisors (4383272213).

21688444315 is an equidigital number, since it uses as much as digits as its factorization.

21688444315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7597229.

The product of its digits is 737280, while the sum is 46.

The spelling of 21688444315 in words is "twenty-one billion, six hundred eighty-eight million, four hundred forty-four thousand, three hundred fifteen".