138531400 has 96 divisors (see below), whose sum is σ = 375243840. Its totient is φ = 46575360.

The previous prime is 138531389. The next prime is 138531401. The reversal of 138531400 is 4135831.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (138531401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73267 + ... + 75133.

It is an arithmetic number, because the mean of its divisors is an integer number (3908790).

Almost surely, 2^138531400 is an apocalyptic number.

138531400 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 138531400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (187621920).

138531400 is an abundant number, since it is smaller than the sum of its proper divisors (236712440).

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

138531400 is a wasteful number, since it uses less digits than its factorization.

138531400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1943 (or 1934 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 138531400 is about 11769.9362785021. The cubic root of 138531400 is about 517.4273821261.

The spelling of 138531400 in words is "one hundred thirty-eight million, five hundred thirty-one thousand, four hundred".