18402020002 has 4 divisors (see below), whose sum is σ = 27603030006. Its totient is φ = 9201010000.

The previous prime is 18402019991. The next prime is 18402020003. The reversal of 18402020002 is 20002020481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20002020481 = 43 ⋅465163267.

It can be written as a sum of positive squares in only one way, i.e., 15247063441 + 3154956561 = 123479^2 + 56169^2 .

It is not an unprimeable number, because it can be changed into a prime (18402020003) 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, 4600504999 + ... + 4600505002.

Almost surely, 2^18402020002 is an apocalyptic number.

18402020002 is a deficient number, since it is larger than the sum of its proper divisors (9201010004).

18402020002 is an equidigital number, since it uses as much as digits as its factorization.

18402020002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9201010003.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 18402020002 its reverse (20002020481), we get a palindrome (38404040483).

The spelling of 18402020002 in words is "eighteen billion, four hundred two million, twenty thousand, two".