18809785850625 has 405 divisors, whose sum is σ = 43468977981429. Its totient is φ = 7806645000000.

The previous prime is 18809785850623. The next prime is 18809785850627. The reversal of 18809785850625 is 52605858790881.

The square root of 18809785850625 is 4337025.

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

18809785850625 is a `hidden beast` number, since 1 + 8 + 8 + 0 + 97 + 8 + 5 + 8 + 506 + 25 = 666.

It is an interprime number because it is at equal distance from previous prime (18809785850623) and next prime (18809785850627).

It can be written as a sum of positive squares in 2 ways, for example, as 1474687210689 + 17335098639936 = 1214367^2 + 4163544^2 .

It is not a de Polignac number, because 18809785850625 - 2¹ = 18809785850623 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18809785850623) by changing a digit.

It is a polite number, since it can be written in 404 ways as a sum of consecutive naturals, for example, 25046319000 + ... + 25046319750.

Almost surely, 2^{18809785850625} is an apocalyptic number.

18809785850625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18809785850625 is the 4337025-th square number.

18809785850625 is the 2168513-rd centered octagonal number.

It is an amenable number.

18809785850625 is an abundant number, since it is smaller than the sum of its proper divisors (24659192130804).

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

18809785850625 is an frugal number, since it uses more digits than its factorization.

18809785850625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564 (or 777 counting only the distinct ones).

The product of its (nonzero) digits is 387072000, while the sum is 72.

The spelling of 18809785850625 in words is "eighteen trillion, eight hundred nine billion, seven hundred eighty-five million, eight hundred fifty thousand, six hundred twenty-five".