138777640 has 16 divisors (see below), whose sum is σ = 312249780. Its totient is φ = 55511040.

The previous prime is 138777637. The next prime is 138777643. The reversal of 138777640 is 46777831.

It is an interprime number because it is at equal distance from previous prime (138777637) and next prime (138777643).

It can be written as a sum of positive squares in 2 ways, for example, as 138250564 + 527076 = 11758^2 + 726^2 .

It is not an unprimeable number, because it can be changed into a prime (138777643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1734681 + ... + 1734760.

Almost surely, 2^138777640 is an apocalyptic number.

138777640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138777640 is an abundant number, since it is smaller than the sum of its proper divisors (173472140).

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

138777640 is a wasteful number, since it uses less digits than its factorization.

138777640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3469452 (or 3469448 counting only the distinct ones).

The product of its (nonzero) digits is 197568, while the sum is 43.

The square root of 138777640 is about 11780.3921836244. The cubic root of 138777640 is about 517.7337769258.

The spelling of 138777640 in words is "one hundred thirty-eight million, seven hundred seventy-seven thousand, six hundred forty".