18513399398400 has 1215 divisors, whose sum is σ = 69703931139661. Its totient is φ = 4877425704960.

The previous prime is 18513399398341. The next prime is 18513399398423. The reversal of 18513399398400 is 489399331581.

The square root of 18513399398400 is 4302720.

It is a perfect power (a square), and thus also a powerful number.

18513399398400 is a `hidden beast` number, since 1 + 8 + 5 + 133 + 9 + 9 + 3 + 98 + 400 = 666.

It can be written as a sum of positive squares in only one way, i.e., 6664823783424 + 11848575614976 = 2581632^2 + 3442176^2 .

It is a tau number, because it is divible by the number of its divisors (1215).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 223053004759 + ... + 223053004841.

Almost surely, 2^{18513399398400} is an apocalyptic number.

18513399398400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18513399398400 is the 4302720-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18513399398400

18513399398400 is an abundant number, since it is smaller than the sum of its proper divisors (51190531741261).

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

18513399398400 is an frugal number, since it uses more digits than its factorization.

18513399398400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228 (or 93 counting only the distinct ones).

The product of its (nonzero) digits is 25194240, while the sum is 63.

The spelling of 18513399398400 in words is "eighteen trillion, five hundred thirteen billion, three hundred ninety-nine million, three hundred ninety-eight thousand, four hundred".