18681391869 has 16 divisors (see below), whose sum is σ = 29965140480. Its totient is φ = 10113234480.

The previous prime is 18681391853. The next prime is 18681391873. The reversal of 18681391869 is 96819318681.

It is not a de Polignac number, because 18681391869 - 2⁴ = 18681391853 is a prime.

It is a super-2 number, since 2×18681391869² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18681391879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23409867 + ... + 23410664.

It is an arithmetic number, because the mean of its divisors is an integer number (1872821280).

Almost surely, 2^18681391869 is an apocalyptic number.

18681391869 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18681391869 is a deficient number, since it is larger than the sum of its proper divisors (11283748611).

18681391869 is a wasteful number, since it uses less digits than its factorization.

18681391869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46820560.

The product of its digits is 4478976, while the sum is 60.

The spelling of 18681391869 in words is "eighteen billion, six hundred eighty-one million, three hundred ninety-one thousand, eight hundred sixty-nine".