7638888891 has 8 divisors (see below), whose sum is σ = 10194038784. Its totient is φ = 5088165800.

The previous prime is 7638888857. The next prime is 7638888893. The reversal of 7638888891 is 1988888367.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7638888891 - 2¹⁵ = 7638856123 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7638888893) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1102671 + ... + 1109576.

It is an arithmetic number, because the mean of its divisors is an integer number (1274254848).

Almost surely, 2^7638888891 is an apocalyptic number.

7638888891 is a deficient number, since it is larger than the sum of its proper divisors (2555149893).

7638888891 is a wasteful number, since it uses less digits than its factorization.

7638888891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2213401.

The product of its digits is 37158912, while the sum is 66.

The square root of 7638888891 is about 87400.7373595898. The cubic root of 7638888891 is about 1969.4429176273.

The spelling of 7638888891 in words is "seven billion, six hundred thirty-eight million, eight hundred eighty-eight thousand, eight hundred ninety-one".