18284894681 has 4 divisors (see below), whose sum is σ = 18730867764. Its totient is φ = 17838921600.

The previous prime is 18284894669. The next prime is 18284894737. The reversal of 18284894681 is 18649848281.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1710649600 + 16574245081 = 41360^2 + 128741^2 .

It is a cyclic number.

It is not a de Polignac number, because 18284894681 - 2²² = 18280700377 is a prime.

It is a super-2 number, since 2×18284894681² (a number of 21 digits) contains 22 as substring.

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 18284894681.

It is not an unprimeable number, because it can be changed into a prime (18284899681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222986480 + ... + 222986561.

It is an arithmetic number, because the mean of its divisors is an integer number (4682716941).

Almost surely, 2^18284894681 is an apocalyptic number.

It is an amenable number.

18284894681 is a deficient number, since it is larger than the sum of its proper divisors (445973083).

18284894681 is an equidigital number, since it uses as much as digits as its factorization.

18284894681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445973082.

The product of its digits is 7077888, while the sum is 59.

The spelling of 18284894681 in words is "eighteen billion, two hundred eighty-four million, eight hundred ninety-four thousand, six hundred eighty-one".