138478860 has 288 divisors, whose sum is σ = 493129728. Its totient is φ = 31173120.

The previous prime is 138478817. The next prime is 138478913. The reversal of 138478860 is 68874831.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1668379 + ... + 1668461.

It is an arithmetic number, because the mean of its divisors is an integer number (1712256).

Almost surely, 2^138478860 is an apocalyptic number.

138478860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138478860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (246564864).

138478860 is an abundant number, since it is smaller than the sum of its proper divisors (354650868).

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

138478860 is a wasteful number, since it uses less digits than its factorization.

138478860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 160 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The square root of 138478860 is about 11767.7041091285. The cubic root of 138478860 is about 517.3619599613.

The spelling of 138478860 in words is "one hundred thirty-eight million, four hundred seventy-eight thousand, eight hundred sixty".