18691257155 has 16 divisors (see below), whose sum is σ = 23772307680. Its totient is φ = 14059540992.

The previous prime is 18691257077. The next prime is 18691257203. The reversal of 18691257155 is 55175219681.

It is a cyclic number.

It is not a de Polignac number, because 18691257155 - 2¹⁶ = 18691191619 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 21284 + ... + 194513.

It is an arithmetic number, because the mean of its divisors is an integer number (1485769230).

Almost surely, 2^18691257155 is an apocalyptic number.

18691257155 is a deficient number, since it is larger than the sum of its proper divisors (5081050525).

18691257155 is a wasteful number, since it uses less digits than its factorization.

18691257155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216838.

The product of its digits is 756000, while the sum is 50.

The spelling of 18691257155 in words is "eighteen billion, six hundred ninety-one million, two hundred fifty-seven thousand, one hundred fifty-five".