18671856025 has 9 divisors (see below), whose sum is σ = 23153948701. Its totient is φ = 14936938240.

The previous prime is 18671856013. The next prime is 18671856089. The reversal of 18671856025 is 52065817681.

The square root of 18671856025 is 136645.

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

It can be written as a sum of positive squares in 4 ways, for example, as 501894409 + 18169961616 = 22403^2 + 134796^2 .

It is not a de Polignac number, because 18671856025 - 2¹⁹ = 18671331737 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18671856025.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 669561 + ... + 696889.

Almost surely, 2^18671856025 is an apocalyptic number.

18671856025 is the 136645-th square number.

18671856025 is the 68323-rd centered octagonal number.

It is an amenable number.

18671856025 is a deficient number, since it is larger than the sum of its proper divisors (4482092676).

18671856025 is an frugal number, since it uses more digits than its factorization.

18671856025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54668 (or 27334 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 49.

Multiplying 18671856025 by its sum of digits (49), we get a square (914920945225 = 956515²).

The spelling of 18671856025 in words is "eighteen billion, six hundred seventy-one million, eight hundred fifty-six thousand, twenty-five".