138671649 has 48 divisors (see below), whose sum is σ = 220746240. Its totient is φ = 85942080.

The previous prime is 138671647. The next prime is 138671651. The reversal of 138671649 is 946176831.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (138671647) and next prime (138671651).

It is not a de Polignac number, because 138671649 - 2¹ = 138671647 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138671647) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 703819 + ... + 704015.

It is an arithmetic number, because the mean of its divisors is an integer number (4598880).

Almost surely, 2^138671649 is an apocalyptic number.

It is an amenable number.

138671649 is a deficient number, since it is larger than the sum of its proper divisors (82074591).

138671649 is a wasteful number, since it uses less digits than its factorization.

138671649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 260 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 138671649 is about 11775.8927050139. The cubic root of 138671649 is about 517.6019374909.

The spelling of 138671649 in words is "one hundred thirty-eight million, six hundred seventy-one thousand, six hundred forty-nine".