21818088666901 has 4 divisors (see below), whose sum is σ = 21818100438112. Its totient is φ = 21818076895692.

The previous prime is 21818088666797. The next prime is 21818088666929. The reversal of 21818088666901 is 10966688081812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21818088666901 - 2²⁷ = 21817954449173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21818088666931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2428425 + ... + 7037998.

It is an arithmetic number, because the mean of its divisors is an integer number (5454525109528).

Almost surely, 2^{21818088666901} is an apocalyptic number.

It is an amenable number.

21818088666901 is a deficient number, since it is larger than the sum of its proper divisors (11771211).

21818088666901 is an equidigital number, since it uses as much as digits as its factorization.

21818088666901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11771210.

The product of its (nonzero) digits is 15925248, while the sum is 64.

The spelling of 21818088666901 in words is "twenty-one trillion, eight hundred eighteen billion, eighty-eight million, six hundred sixty-six thousand, nine hundred one".