138682690 has 8 divisors (see below), whose sum is σ = 249628860. Its totient is φ = 55473072.

The previous prime is 138682673. The next prime is 138682693. The reversal of 138682690 is 96286831.

It can be written as a sum of positive squares in 2 ways, for example, as 117310561 + 21372129 = 10831^2 + 4623^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×138682690² = 38465777011272200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138682693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6934125 + ... + 6934144.

Almost surely, 2^138682690 is an apocalyptic number.

138682690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138682690 is a deficient number, since it is larger than the sum of its proper divisors (110946170).

138682690 is a wasteful number, since it uses less digits than its factorization.

138682690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13868276.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 138682690 is about 11776.3614924135. The cubic root of 138682690 is about 517.6156742361.

The spelling of 138682690 in words is "one hundred thirty-eight million, six hundred eighty-two thousand, six hundred ninety".