139218307 has 4 divisors (see below), whose sum is σ = 140895720. Its totient is φ = 137540896.

The previous prime is 139218293. The next prime is 139218323. The reversal of 139218307 is 703812931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 703812931 = 8707 ⋅80833.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139218307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139218367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 838582 + ... + 838747.

It is an arithmetic number, because the mean of its divisors is an integer number (35223930).

Almost surely, 2^139218307 is an apocalyptic number.

139218307 is a deficient number, since it is larger than the sum of its proper divisors (1677413).

139218307 is an equidigital number, since it uses as much as digits as its factorization.

139218307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1677412.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 139218307 is about 11799.0807692803. The cubic root of 139218307 is about 518.2811925187.

The spelling of 139218307 in words is "one hundred thirty-nine million, two hundred eighteen thousand, three hundred seven".