18821333506 has 4 divisors (see below), whose sum is σ = 28232000262. Its totient is φ = 9410666752.

The previous prime is 18821333497. The next prime is 18821333507. The reversal of 18821333506 is 60533312881.

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

It can be written as a sum of positive squares in only one way, i.e., 15143517481 + 3677816025 = 123059^2 + 60645^2 .

It is not an unprimeable number, because it can be changed into a prime (18821333507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4705333375 + ... + 4705333378.

Almost surely, 2^18821333506 is an apocalyptic number.

18821333506 is a deficient number, since it is larger than the sum of its proper divisors (9410666756).

18821333506 is an equidigital number, since it uses as much as digits as its factorization.

18821333506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9410666755.

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 18821333506 in words is "eighteen billion, eight hundred twenty-one million, three hundred thirty-three thousand, five hundred six".