138463640 has 128 divisors (see below), whose sum is σ = 397094400. Its totient is φ = 42301440.

The previous prime is 138463597. The next prime is 138463643. The reversal of 138463640 is 46364831.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 138463640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138463643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 89675 + ... + 91205.

It is an arithmetic number, because the mean of its divisors is an integer number (3102300).

Almost surely, 2^138463640 is an apocalyptic number.

138463640 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 138463640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198547200).

138463640 is an abundant number, since it is smaller than the sum of its proper divisors (258630760).

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

138463640 is a wasteful number, since it uses less digits than its factorization.

138463640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1585 (or 1581 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 138463640 is about 11767.0574061657. The cubic root of 138463640 is about 517.3430051126.

The spelling of 138463640 in words is "one hundred thirty-eight million, four hundred sixty-three thousand, six hundred forty".