18708621990 has 16 divisors (see below), whose sum is σ = 44900692848. Its totient is φ = 4988965856.

The previous prime is 18708621979. The next prime is 18708622001. The reversal of 18708621990 is 9912680781.

It is an interprime number because it is at equal distance from previous prime (18708621979) and next prime (18708622001).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 311810337 + ... + 311810396.

It is an arithmetic number, because the mean of its divisors is an integer number (2806293303).

Almost surely, 2^18708621990 is an apocalyptic number.

18708621990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18708621990 is an abundant number, since it is smaller than the sum of its proper divisors (26192070858).

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

18708621990 is a wasteful number, since it uses less digits than its factorization.

18708621990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 623620743.

The product of its (nonzero) digits is 435456, while the sum is 51.

The spelling of 18708621990 in words is "eighteen billion, seven hundred eight million, six hundred twenty-one thousand, nine hundred ninety".