18945399000 has 512 divisors, whose sum is σ = 68200704000. Its totient is φ = 4333824000.

The previous prime is 18945398999. The next prime is 18945399013. The reversal of 18945399000 is 99354981.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 82730886 + ... + 82731114.

It is an arithmetic number, because the mean of its divisors is an integer number (133204500).

Almost surely, 2^18945399000 is an apocalyptic number.

18945399000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18945399000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34100352000).

18945399000 is an abundant number, since it is smaller than the sum of its proper divisors (49255305000).

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

18945399000 is a wasteful number, since it uses less digits than its factorization.

18945399000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396 (or 382 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 48.

The spelling of 18945399000 in words is "eighteen billion, nine hundred forty-five million, three hundred ninety-nine thousand".