21663419555 has 8 divisors (see below), whose sum is σ = 26239058352. Its totient is φ = 17168765728.

The previous prime is 21663419513. The next prime is 21663419593. The reversal of 21663419555 is 55591436612.

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 21663419555 - 2⁸ = 21663419299 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 20245652 + ... + 20246721.

It is an arithmetic number, because the mean of its divisors is an integer number (3279882294).

Almost surely, 2^21663419555 is an apocalyptic number.

21663419555 is a deficient number, since it is larger than the sum of its proper divisors (4575638797).

21663419555 is a wasteful number, since it uses less digits than its factorization.

21663419555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40492485.

The product of its digits is 972000, while the sum is 47.

The spelling of 21663419555 in words is "twenty-one billion, six hundred sixty-three million, four hundred nineteen thousand, five hundred fifty-five".