8640138 has 16 divisors (see below), whose sum is σ = 18609696. Its totient is φ = 2658480.

The previous prime is 8640133. The next prime is 8640161. The reversal of 8640138 is 8310468.

It is a happy number.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (8640133) 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 in 7 ways as a sum of consecutive naturals, for example, 55308 + ... + 55463.

It is an arithmetic number, because the mean of its divisors is an integer number (1163106).

Almost surely, 2^8640138 is an apocalyptic number.

8640138 is an abundant number, since it is smaller than the sum of its proper divisors (9969558).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8640138 is a wasteful number, since it uses less digits than its factorization.

8640138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110789.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 8640138 is about 2939.4111655228. The cubic root of 8640138 is about 205.1982060800.

It can be divided in two parts, 8640 and 138, that added together give a palindrome (8778).

The spelling of 8640138 in words is "eight million, six hundred forty thousand, one hundred thirty-eight".