138668400 has 180 divisors, whose sum is σ = 518409528. Its totient is φ = 34122240.

The previous prime is 138668399. The next prime is 138668407. The reversal of 138668400 is 4866831.

It is a happy number.

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 (138668407) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 45319 + ... + 48281.

Almost surely, 2^138668400 is an apocalyptic number.

138668400 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 138668400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (259204764).

138668400 is an abundant number, since it is smaller than the sum of its proper divisors (379741128).

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

138668400 is a wasteful number, since it uses less digits than its factorization.

138668400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3000 (or 2986 counting only the distinct ones).

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

The square root of 138668400 is about 11775.7547528810. The cubic root of 138668400 is about 517.5978950837.

The spelling of 138668400 in words is "one hundred thirty-eight million, six hundred sixty-eight thousand, four hundred".