138660429 has 4 divisors (see below), whose sum is σ = 184880576. Its totient is φ = 92440284.

The previous prime is 138660413. The next prime is 138660437. The reversal of 138660429 is 924066831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 924066831 = 3 ⋅308022277.

It is not a de Polignac number, because 138660429 - 2⁴ = 138660413 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138660409) 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, 23110069 + ... + 23110074.

It is an arithmetic number, because the mean of its divisors is an integer number (46220144).

Almost surely, 2^138660429 is an apocalyptic number.

It is an amenable number.

138660429 is a deficient number, since it is larger than the sum of its proper divisors (46220147).

138660429 is an equidigital number, since it uses as much as digits as its factorization.

138660429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46220146.

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 138660429 is about 11775.4162983735. The cubic root of 138660429 is about 517.5879772945.

The spelling of 138660429 in words is "one hundred thirty-eight million, six hundred sixty thousand, four hundred twenty-nine".