139405745 has 4 divisors (see below), whose sum is σ = 167286900. Its totient is φ = 111524592.

The previous prime is 139405733. The next prime is 139405757. The reversal of 139405745 is 547504931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 547504931 = 19 ⋅28816049.

It is an interprime number because it is at equal distance from previous prime (139405733) and next prime (139405757).

It can be written as a sum of positive squares in 2 ways, for example, as 61842496 + 77563249 = 7864^2 + 8807^2 .

It is a cyclic number.

It is not a de Polignac number, because 139405745 - 2¹⁰ = 139404721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 139405699 and 139405708.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13940570 + ... + 13940579.

It is an arithmetic number, because the mean of its divisors is an integer number (41821725).

Almost surely, 2^139405745 is an apocalyptic number.

It is an amenable number.

139405745 is a deficient number, since it is larger than the sum of its proper divisors (27881155).

139405745 is an equidigital number, since it uses as much as digits as its factorization.

139405745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27881154.

The product of its (nonzero) digits is 75600, while the sum is 38.

The square root of 139405745 is about 11807.0210044702. The cubic root of 139405745 is about 518.5136859486.

The spelling of 139405745 in words is "one hundred thirty-nine million, four hundred five thousand, seven hundred forty-five".