18900005644 has 12 divisors (see below), whose sum is σ = 35619241504. Its totient is φ = 8723079504.

The previous prime is 18900005633. The next prime is 18900005647. The reversal of 18900005644 is 44650000981.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (18900005647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181730772 + ... + 181730875.

Almost surely, 2^18900005644 is an apocalyptic number.

It is an amenable number.

18900005644 is a deficient number, since it is larger than the sum of its proper divisors (16719235860).

18900005644 is a wasteful number, since it uses less digits than its factorization.

18900005644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363461664 (or 363461662 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The spelling of 18900005644 in words is "eighteen billion, nine hundred million, five thousand, six hundred forty-four".