138943799 has 4 divisors (see below), whose sum is σ = 138991440. Its totient is φ = 138896160.

The previous prime is 138943757. The next prime is 138943813. The reversal of 138943799 is 997349831.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138943799 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138943799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138943199) 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, 19139 + ... + 25380.

It is an arithmetic number, because the mean of its divisors is an integer number (34747860).

Almost surely, 2^138943799 is an apocalyptic number.

138943799 is a deficient number, since it is larger than the sum of its proper divisors (47641).

138943799 is an equidigital number, since it uses as much as digits as its factorization.

138943799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47640.

The product of its digits is 1469664, while the sum is 53.

The square root of 138943799 is about 11787.4424282793. The cubic root of 138943799 is about 517.9403227265.

The spelling of 138943799 in words is "one hundred thirty-eight million, nine hundred forty-three thousand, seven hundred ninety-nine".