138864258 has 72 divisors (see below), whose sum is σ = 328872960. Its totient is φ = 42325920.

The previous prime is 138864241. The next prime is 138864259. The reversal of 138864258 is 852468831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138864259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 580903 + ... + 581141.

It is an arithmetic number, because the mean of its divisors is an integer number (4567680).

Almost surely, 2^138864258 is an apocalyptic number.

138864258 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 138864258, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164436480).

138864258 is an abundant number, since it is smaller than the sum of its proper divisors (190008702).

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

138864258 is a wasteful number, since it uses less digits than its factorization.

138864258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464 (or 448 counting only the distinct ones).

The product of its digits is 368640, while the sum is 45.

The square root of 138864258 is about 11784.0679733274. The cubic root of 138864258 is about 517.8414689563.

The spelling of 138864258 in words is "one hundred thirty-eight million, eight hundred sixty-four thousand, two hundred fifty-eight".