138706423 has 2 divisors, whose sum is σ = 138706424. Its totient is φ = 138706422.

The previous prime is 138706409. The next prime is 138706429. The reversal of 138706423 is 324607831.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138706423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138706429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69353211 + 69353212.

It is an arithmetic number, because the mean of its divisors is an integer number (69353212).

Almost surely, 2^138706423 is an apocalyptic number.

138706423 is a deficient number, since it is larger than the sum of its proper divisors (1).

138706423 is an equidigital number, since it uses as much as digits as its factorization.

138706423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 138706423 is about 11777.3691034968. The cubic root of 138706423 is about 517.6451993631.

It can be divided in two parts, 138706 and 423, that added together give a square (139129 = 373²).

The spelling of 138706423 in words is "one hundred thirty-eight million, seven hundred six thousand, four hundred twenty-three".