118643409990491 has 4 divisors (see below), whose sum is σ = 118985321835192. Its totient is φ = 118301498145792.

The previous prime is 118643409990433. The next prime is 118643409990509. The reversal of 118643409990491 is 194099904346811.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 118643409990491 - 2²² = 118643405796187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (118643409990431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170955921830 + ... + 170955922523.

It is an arithmetic number, because the mean of its divisors is an integer number (29746330458798).

Almost surely, 2^{118643409990491} is an apocalyptic number.

118643409990491 is a deficient number, since it is larger than the sum of its proper divisors (341911844701).

118643409990491 is an equidigital number, since it uses as much as digits as its factorization.

118643409990491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341911844700.

The product of its (nonzero) digits is 60466176, while the sum is 68.

The spelling of 118643409990491 in words is "one hundred eighteen trillion, six hundred forty-three billion, four hundred nine million, nine hundred ninety thousand, four hundred ninety-one".