21685443374 has 8 divisors (see below), whose sum is σ = 37175045808. Its totient is φ = 9293761440.

The previous prime is 21685443371. The next prime is 21685443379. The reversal of 21685443374 is 47334458612.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21685443371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 774480107 + ... + 774480134.

It is an arithmetic number, because the mean of its divisors is an integer number (4646880726).

Almost surely, 2^21685443374 is an apocalyptic number.

21685443374 is a deficient number, since it is larger than the sum of its proper divisors (15489602434).

21685443374 is a wasteful number, since it uses less digits than its factorization.

21685443374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1548960250.

The product of its digits is 1935360, while the sum is 47.

The spelling of 21685443374 in words is "twenty-one billion, six hundred eighty-five million, four hundred forty-three thousand, three hundred seventy-four".