18935187658 has 4 divisors (see below), whose sum is σ = 28402781490. Its totient is φ = 9467593828.

The previous prime is 18935187641. The next prime is 18935187659. The reversal of 18935187658 is 85678153981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 85678153981 = 7 ⋅12239736283.

It can be written as a sum of positive squares in only one way, i.e., 17117273889 + 1817913769 = 130833^2 + 42637^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18935187596 and 18935187605.

It is not an unprimeable number, because it can be changed into a prime (18935187659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4733796913 + ... + 4733796916.

Almost surely, 2^18935187658 is an apocalyptic number.

18935187658 is a deficient number, since it is larger than the sum of its proper divisors (9467593832).

18935187658 is an equidigital number, since it uses as much as digits as its factorization.

18935187658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9467593831.

The product of its digits is 14515200, while the sum is 61.

The spelling of 18935187658 in words is "eighteen billion, nine hundred thirty-five million, one hundred eighty-seven thousand, six hundred fifty-eight".