138949218 has 12 divisors (see below), whose sum is σ = 301056678. Its totient is φ = 46316400.

The previous prime is 138949193. The next prime is 138949219. The reversal of 138949218 is 812949831.

It can be written as a sum of positive squares in only one way, i.e., 75220929 + 63728289 = 8673^2 + 7983^2 .

It is not an unprimeable number, because it can be changed into a prime (138949219) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3859683 + ... + 3859718.

Almost surely, 2^138949218 is an apocalyptic number.

138949218 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

138949218 is an abundant number, since it is smaller than the sum of its proper divisors (162107460).

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

138949218 is a wasteful number, since it uses less digits than its factorization.

138949218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7719409 (or 7719406 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 138949218 is about 11787.6722893029. The cubic root of 138949218 is about 517.9470561016.

The spelling of 138949218 in words is "one hundred thirty-eight million, nine hundred forty-nine thousand, two hundred eighteen".