139444447 has 4 divisors (see below), whose sum is σ = 139768416. Its totient is φ = 139120480.

The previous prime is 139444429. The next prime is 139444471. The reversal of 139444447 is 744444931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 744444931 = 1151 ⋅646781.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139444447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139444427) 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, 161338 + ... + 162199.

It is an arithmetic number, because the mean of its divisors is an integer number (34942104).

Almost surely, 2^139444447 is an apocalyptic number.

139444447 is a deficient number, since it is larger than the sum of its proper divisors (323969).

139444447 is an equidigital number, since it uses as much as digits as its factorization.

139444447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323968.

The product of its digits is 193536, while the sum is 40.

The square root of 139444447 is about 11808.6598308191. The cubic root of 139444447 is about 518.5616649849.

The spelling of 139444447 in words is "one hundred thirty-nine million, four hundred forty-four thousand, four hundred forty-seven".