138268649 has 4 divisors (see below), whose sum is σ = 142728960. Its totient is φ = 133808340.

The previous prime is 138268631. The next prime is 138268661. The reversal of 138268649 is 946862831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 946862831 = 24763 ⋅38237.

It is a cyclic number.

It is not a de Polignac number, because 138268649 - 2⁸ = 138268393 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138268699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2230109 + ... + 2230170.

It is an arithmetic number, because the mean of its divisors is an integer number (35682240).

Almost surely, 2^138268649 is an apocalyptic number.

It is an amenable number.

138268649 is a deficient number, since it is larger than the sum of its proper divisors (4460311).

138268649 is an equidigital number, since it uses as much as digits as its factorization.

138268649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4460310.

The product of its digits is 497664, while the sum is 47.

The square root of 138268649 is about 11758.7690257101. The cubic root of 138268649 is about 517.1000421216.

The spelling of 138268649 in words is "one hundred thirty-eight million, two hundred sixty-eight thousand, six hundred forty-nine".