18188396644 has 24 divisors (see below), whose sum is σ = 34728861888. Its totient is φ = 8266129440.

The previous prime is 18188396617. The next prime is 18188396717. The reversal of 18188396644 is 44669388181.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 277654 + ... + 336850.

It is an arithmetic number, because the mean of its divisors is an integer number (1447035912).

Almost surely, 2^18188396644 is an apocalyptic number.

It is an amenable number.

18188396644 is a deficient number, since it is larger than the sum of its proper divisors (16540465244).

18188396644 is a wasteful number, since it uses less digits than its factorization.

18188396644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66195 (or 66193 counting only the distinct ones).

The product of its digits is 7962624, while the sum is 58.

The spelling of 18188396644 in words is "eighteen billion, one hundred eighty-eight million, three hundred ninety-six thousand, six hundred forty-four".