138406407 has 4 divisors (see below), whose sum is σ = 184541880. Its totient is φ = 92270936.

The previous prime is 138406369. The next prime is 138406421. The reversal of 138406407 is 704604831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138406407 - 2¹⁰ = 138405383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138406007) 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, 23067732 + ... + 23067737.

It is an arithmetic number, because the mean of its divisors is an integer number (46135470).

Almost surely, 2^138406407 is an apocalyptic number.

138406407 is a deficient number, since it is larger than the sum of its proper divisors (46135473).

138406407 is an equidigital number, since it uses as much as digits as its factorization.

138406407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46135472.

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 138406407 is about 11764.6252384001. The cubic root of 138406407 is about 517.2717152232.

The spelling of 138406407 in words is "one hundred thirty-eight million, four hundred six thousand, four hundred seven".