21664015443354 has 8 divisors (see below), whose sum is σ = 43328030886720. Its totient is φ = 7221338481116.

The previous prime is 21664015443307. The next prime is 21664015443379. The reversal of 21664015443354 is 45334451046612.

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

21664015443354 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1805334620274 + ... + 1805334620285.

It is an arithmetic number, because the mean of its divisors is an integer number (5416003860840).

Almost surely, 2^{21664015443354} is an apocalyptic number.

21664015443354 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21664015443354 is a wasteful number, since it uses less digits than its factorization.

21664015443354 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3610669240564.

The product of its (nonzero) digits is 4147200, while the sum is 48.

Adding to 21664015443354 its reverse (45334451046612), we get a palindrome (66998466489966).

The spelling of 21664015443354 in words is "twenty-one trillion, six hundred sixty-four billion, fifteen million, four hundred forty-three thousand, three hundred fifty-four".