21418219855 has 4 divisors (see below), whose sum is σ = 25701863832. Its totient is φ = 17134575880.

The previous prime is 21418219843. The next prime is 21418219877. The reversal of 21418219855 is 55891281412.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21418219855 - 2⁹ = 21418219343 is a prime.

It is a Duffinian number.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 2141821981 + ... + 2141821990.

It is an arithmetic number, because the mean of its divisors is an integer number (6425465958).

Almost surely, 2^21418219855 is an apocalyptic number.

21418219855 is a deficient number, since it is larger than the sum of its proper divisors (4283643977).

21418219855 is an equidigital number, since it uses as much as digits as its factorization.

21418219855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4283643976.

The product of its digits is 230400, while the sum is 46.

The spelling of 21418219855 in words is "twenty-one billion, four hundred eighteen million, two hundred nineteen thousand, eight hundred fifty-five".