138866400 has 180 divisors, whose sum is σ = 506655072. Its totient is φ = 37013760.

The previous prime is 138866381. The next prime is 138866401. The reversal of 138866400 is 4668831.

It is a happy number.

138866400 is a `hidden beast` number, since 1 + 3 + 8 + 8 + 6 + 640 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138866401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 63729 + ... + 65871.

Almost surely, 2^138866400 is an apocalyptic number.

138866400 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 138866400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253327536).

138866400 is an abundant number, since it is smaller than the sum of its proper divisors (367788672).

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

138866400 is a wasteful number, since it uses less digits than its factorization.

138866400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2175 (or 2153 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 138866400 is about 11784.1588583997. The cubic root of 138866400 is about 517.8441315343.

The spelling of 138866400 in words is "one hundred thirty-eight million, eight hundred sixty-six thousand, four hundred".