138277440 has 336 divisors, whose sum is σ = 573755520. Its totient is φ = 29942784.

The previous prime is 138277429. The next prime is 138277457. The reversal of 138277440 is 44772831.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (336).

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

It is a junction number, because it is equal to n+sod(n) for n = 138277395 and 138277404.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7277751 + ... + 7277769.

Almost surely, 2^138277440 is an apocalyptic number.

138277440 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 138277440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286877760).

138277440 is an abundant number, since it is smaller than the sum of its proper divisors (435478080).

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

138277440 is an equidigital number, since it uses as much as digits as its factorization.

138277440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 138277440 is about 11759.1428259036. The cubic root of 138277440 is about 517.1110008125. Note that the first 3 decimals are identical.

The spelling of 138277440 in words is "one hundred thirty-eight million, two hundred seventy-seven thousand, four hundred forty".