138632216789491 has 4 divisors (see below), whose sum is σ = 140904876081184. Its totient is φ = 136359557497800.

The previous prime is 138632216789467. The next prime is 138632216789501. The reversal of 138632216789491 is 194987612236831.

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 138632216789491 - 2²³ = 138632208400883 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138632216789491.

It is not an unprimeable number, because it can be changed into a prime (138632216789401) 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 3 ways as a sum of consecutive naturals, for example, 1136329645755 + ... + 1136329645876.

It is an arithmetic number, because the mean of its divisors is an integer number (35226219020296).

Almost surely, 2^{138632216789491} is an apocalyptic number.

138632216789491 is a deficient number, since it is larger than the sum of its proper divisors (2272659291693).

138632216789491 is an equidigital number, since it uses as much as digits as its factorization.

138632216789491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2272659291692.

The product of its digits is 188116992, while the sum is 70.

The spelling of 138632216789491 in words is "one hundred thirty-eight trillion, six hundred thirty-two billion, two hundred sixteen million, seven hundred eighty-nine thousand, four hundred ninety-one".