138421849 has 4 divisors (see below), whose sum is σ = 141033636. Its totient is φ = 135810064.

The previous prime is 138421831. The next prime is 138421891. The reversal of 138421849 is 948124831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 948124831 = 3793 ⋅249967.

It can be written as a sum of positive squares in 2 ways, for example, as 61544025 + 76877824 = 7845^2 + 8768^2 .

It is a cyclic number.

It is not a de Polignac number, because 138421849 - 2⁵ = 138421817 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138421819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1305814 + ... + 1305919.

It is an arithmetic number, because the mean of its divisors is an integer number (35258409).

Almost surely, 2^138421849 is an apocalyptic number.

It is an amenable number.

138421849 is a deficient number, since it is larger than the sum of its proper divisors (2611787).

138421849 is an equidigital number, since it uses as much as digits as its factorization.

138421849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2611786.

The product of its digits is 55296, while the sum is 40.

The square root of 138421849 is about 11765.2815095942. The cubic root of 138421849 is about 517.2909518394.

The spelling of 138421849 in words is "one hundred thirty-eight million, four hundred twenty-one thousand, eight hundred forty-nine".