138709829 has 4 divisors (see below), whose sum is σ = 139011180. Its totient is φ = 138408480.

The previous prime is 138709811. The next prime is 138709877. The reversal of 138709829 is 928907831.

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

It can be written as a sum of positive squares in 2 ways, for example, as 43256929 + 95452900 = 6577^2 + 9770^2 .

It is a cyclic number.

It is not a de Polignac number, because 138709829 - 2¹² = 138705733 is a prime.

It is a super-2 number, since 2×138709829² = 38480833322418482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138709429) 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, 149984 + ... + 150905.

It is an arithmetic number, because the mean of its divisors is an integer number (34752795).

Almost surely, 2^138709829 is an apocalyptic number.

It is an amenable number.

138709829 is a deficient number, since it is larger than the sum of its proper divisors (301351).

138709829 is an equidigital number, since it uses as much as digits as its factorization.

138709829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301350.

The product of its (nonzero) digits is 217728, while the sum is 47.

The square root of 138709829 is about 11777.5137019661. The cubic root of 138709829 is about 517.6494363337.

The spelling of 138709829 in words is "one hundred thirty-eight million, seven hundred nine thousand, eight hundred twenty-nine".