18221786802 has 18 divisors (see below), whose sum is σ = 39481778973. Its totient is φ = 6073738032.

The previous prime is 18221786801. The next prime is 18221786827. The reversal of 18221786802 is 20868712281.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14648018841 + 3573767961 = 121029^2 + 59781^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=95451.

It is not an unprimeable number, because it can be changed into a prime (18221786801) 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 8 ways as a sum of consecutive naturals, for example, 556798 + ... + 588614.

Almost surely, 2^18221786802 is an apocalyptic number.

18221786802 is an abundant number, since it is smaller than the sum of its proper divisors (21259992171).

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

18221786802 is an frugal number, since it uses more digits than its factorization.

18221786802 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63642 (or 31822 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 45.

The spelling of 18221786802 in words is "eighteen billion, two hundred twenty-one million, seven hundred eighty-six thousand, eight hundred two".