18220247685 has 96 divisors (see below), whose sum is σ = 33241309920. Its totient is φ = 9223372800.

The previous prime is 18220247671. The next prime is 18220247693. The reversal of 18220247685 is 58674202281.

18220247685 is a `hidden beast` number, since 1 + 82 + 20 + 2 + 476 + 85 = 666.

It can be written as a sum of positive squares in 16 ways, for example, as 13811420484 + 4408827201 = 117522^2 + 66399^2 .

It is not a de Polignac number, because 18220247685 - 2⁷ = 18220247557 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 18220247685.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10916031 + ... + 10917699.

It is an arithmetic number, because the mean of its divisors is an integer number (346263645).

Almost surely, 2^18220247685 is an apocalyptic number.

18220247685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18220247685 is a deficient number, since it is larger than the sum of its proper divisors (15021062235).

18220247685 is a wasteful number, since it uses less digits than its factorization.

18220247685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1879 (or 1876 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 45.

The spelling of 18220247685 in words is "eighteen billion, two hundred twenty million, two hundred forty-seven thousand, six hundred eighty-five".