18643711821487 has 16 divisors (see below), whose sum is σ = 18821659852800. Its totient is φ = 18466616568960.

The previous prime is 18643711821463. The next prime is 18643711821499. The reversal of 18643711821487 is 78412811734681.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18643711821487 is a prime.

It is a super-2 number, since 2×18643711821487² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18643711801487) 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, 717908839 + ... + 717934807.

It is an arithmetic number, because the mean of its divisors is an integer number (1176353740800).

Almost surely, 2^{18643711821487} is an apocalyptic number.

18643711821487 is a deficient number, since it is larger than the sum of its proper divisors (177948031313).

18643711821487 is a wasteful number, since it uses less digits than its factorization.

18643711821487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42126.

The product of its digits is 14450688, while the sum is 61.

The spelling of 18643711821487 in words is "eighteen trillion, six hundred forty-three billion, seven hundred eleven million, eight hundred twenty-one thousand, four hundred eighty-seven".