18691688715640 has 64 divisors (see below), whose sum is σ = 44542316016000. Its totient is φ = 7034956351488.

The previous prime is 18691688715619. The next prime is 18691688715647. The reversal of 18691688715640 is 4651788619681.

It is a self number, because there is not a number n which added to its sum of digits gives 18691688715640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18691688715647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1237440 + ... + 6238159.

It is an arithmetic number, because the mean of its divisors is an integer number (695973687750).

Almost surely, 2^{18691688715640} is an apocalyptic number.

18691688715640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18691688715640 is an abundant number, since it is smaller than the sum of its proper divisors (25850627300360).

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

18691688715640 is a wasteful number, since it uses less digits than its factorization.

18691688715640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7479304 (or 7479300 counting only the distinct ones).

The product of its (nonzero) digits is 139345920, while the sum is 70.

The spelling of 18691688715640 in words is "eighteen trillion, six hundred ninety-one billion, six hundred eighty-eight million, seven hundred fifteen thousand, six hundred forty".