138049690 has 16 divisors (see below), whose sum is σ = 263106792. Its totient is φ = 51971584.

The previous prime is 138049679. The next prime is 138049693. The reversal of 138049690 is 96940831.

It can be written as a sum of positive squares in 4 ways, for example, as 137569441 + 480249 = 11729^2 + 693^2 .

It is a super-2 number, since 2×138049690² = 38115433818192200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138049693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 405859 + ... + 406198.

Almost surely, 2^138049690 is an apocalyptic number.

138049690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138049690 is a deficient number, since it is larger than the sum of its proper divisors (125057102).

138049690 is a wasteful number, since it uses less digits than its factorization.

138049690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 812081.

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 138049690 is about 11749.4548809721. The cubic root of 138049690 is about 516.8269420667.

The spelling of 138049690 in words is "one hundred thirty-eight million, forty-nine thousand, six hundred ninety".