1809147985920 has 1408 divisors, whose sum is σ = 7522802495280. Its totient is φ = 412782428160.

The previous prime is 1809147985901. The next prime is 1809147985999. The reversal of 1809147985920 is 295897419081.

1809147985920 is a `hidden beast` number, since 1 + 8 + 0 + 91 + 479 + 8 + 59 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (1408).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 87 ways as a sum of consecutive naturals, for example, 106420469752 + ... + 106420469768.

Almost surely, 2^{1809147985920} is an apocalyptic number.

1809147985920 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 1809147985920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3761401247640).

1809147985920 is an abundant number, since it is smaller than the sum of its proper divisors (5713654509360).

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

1809147985920 is an frugal number, since it uses more digits than its factorization.

1809147985920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 13063680, while the sum is 63.

The spelling of 1809147985920 in words is "one trillion, eight hundred nine billion, one hundred forty-seven million, nine hundred eighty-five thousand, nine hundred twenty".