18961005618 has 12 divisors (see below), whose sum is σ = 41082178878. Its totient is φ = 6320335200.

The previous prime is 18961005563. The next prime is 18961005653. The reversal of 18961005618 is 81650016981.

18961005618 is a `hidden beast` number, since 1 + 89 + 6 + 1 + 0 + 0 + 561 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16362758889 + 2598246729 = 127917^2 + 50973^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 526694583 + ... + 526694618.

Almost surely, 2^18961005618 is an apocalyptic number.

18961005618 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18961005618 is an abundant number, since it is smaller than the sum of its proper divisors (22121173260).

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

18961005618 is a wasteful number, since it uses less digits than its factorization.

18961005618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1053389209 (or 1053389206 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The spelling of 18961005618 in words is "eighteen billion, nine hundred sixty-one million, five thousand, six hundred eighteen".