108639640 has 32 divisors (see below), whose sum is σ = 246868560. Its totient is φ = 43024000.

The previous prime is 108639637. The next prime is 108639647. The reversal of 108639640 is 46936801.

It is a self number, because there is not a number n which added to its sum of digits gives 108639640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (108639647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9406 + ... + 17485.

Almost surely, 2^108639640 is an apocalyptic number.

108639640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

108639640 is an abundant number, since it is smaller than the sum of its proper divisors (138228920).

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

108639640 is a wasteful number, since it uses less digits than its factorization.

108639640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27003 (or 26999 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 108639640 is about 10423.0341072070. The cubic root of 108639640 is about 477.1586185970.

It can be divided in two parts, 10863 and 9640, that added together give a triangular number (20503 = T₂₀₂).

The spelling of 108639640 in words is "one hundred eight million, six hundred thirty-nine thousand, six hundred forty".