138283840 has 28 divisors (see below), whose sum is σ = 329289156. Its totient is φ = 55313408.

The previous prime is 138283813. The next prime is 138283841. The reversal of 138283840 is 48382831.

It can be written as a sum of positive squares in 2 ways, for example, as 23193856 + 115089984 = 4816^2 + 10728^2 .

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 138283840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138283841) 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, 215749 + ... + 216388.

It is an arithmetic number, because the mean of its divisors is an integer number (11760327).

Almost surely, 2^138283840 is an apocalyptic number.

138283840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138283840 is an abundant number, since it is smaller than the sum of its proper divisors (191005316).

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

138283840 is an equidigital number, since it uses as much as digits as its factorization.

138283840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432154 (or 432144 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 138283840 is about 11759.4149514336. The cubic root of 138283840 is about 517.1189786367.

The spelling of 138283840 in words is "one hundred thirty-eight million, two hundred eighty-three thousand, eight hundred forty".