18278220668 has 24 divisors (see below), whose sum is σ = 32924682000. Its totient is φ = 8872270848.

The previous prime is 18278220643. The next prime is 18278220671. The reversal of 18278220668 is 86602287281.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 71078 + ... + 203981.

It is an arithmetic number, because the mean of its divisors is an integer number (1371861750).

Almost surely, 2^18278220668 is an apocalyptic number.

It is an amenable number.

18278220668 is a deficient number, since it is larger than the sum of its proper divisors (14646461332).

18278220668 is a wasteful number, since it uses less digits than its factorization.

18278220668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275549 (or 275547 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 50.

The spelling of 18278220668 in words is "eighteen billion, two hundred seventy-eight million, two hundred twenty thousand, six hundred sixty-eight".