138406511 has 4 divisors (see below), whose sum is σ = 139027392. Its totient is φ = 137785632.

The previous prime is 138406483. The next prime is 138406519. The reversal of 138406511 is 115604831.

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 138406511 - 2¹⁸ = 138144367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138406519) 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, 310106 + ... + 310551.

It is an arithmetic number, because the mean of its divisors is an integer number (34756848).

Almost surely, 2^138406511 is an apocalyptic number.

138406511 is a deficient number, since it is larger than the sum of its proper divisors (620881).

138406511 is an equidigital number, since it uses as much as digits as its factorization.

138406511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 620880.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 138406511 is about 11764.6296584295. The cubic root of 138406511 is about 517.2718447843.

The spelling of 138406511 in words is "one hundred thirty-eight million, four hundred six thousand, five hundred eleven".