138671380 has 24 divisors (see below), whose sum is σ = 308340648. Its totient is φ = 52205568.

The previous prime is 138671371. The next prime is 138671381. The reversal of 138671380 is 83176831.

It can be written as a sum of positive squares in 4 ways, for example, as 33895684 + 104775696 = 5822^2 + 10236^2 .

It is a super-2 number, since 2×138671380² = 38459503262208800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138671381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 203589 + ... + 204268.

It is an arithmetic number, because the mean of its divisors is an integer number (12847527).

Almost surely, 2^138671380 is an apocalyptic number.

138671380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138671380 is an abundant number, since it is smaller than the sum of its proper divisors (169669268).

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

138671380 is a wasteful number, since it uses less digits than its factorization.

138671380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407883 (or 407881 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 138671380 is about 11775.8812833690. The cubic root of 138671380 is about 517.6016028034.

The spelling of 138671380 in words is "one hundred thirty-eight million, six hundred seventy-one thousand, three hundred eighty".