139172779 has 2 divisors, whose sum is σ = 139172780. Its totient is φ = 139172778.

The previous prime is 139172773. The next prime is 139172797. The reversal of 139172779 is 977271931.

Together with next prime (139172797) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 139172779 - 2¹³ = 139164587 is a prime.

It is not a weakly prime, because it can be changed into another prime (139172773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69586389 + 69586390.

It is an arithmetic number, because the mean of its divisors is an integer number (69586390).

Almost surely, 2^139172779 is an apocalyptic number.

139172779 is a deficient number, since it is larger than the sum of its proper divisors (1).

139172779 is an equidigital number, since it uses as much as digits as its factorization.

139172779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 166698, while the sum is 46.

The square root of 139172779 is about 11797.1513086847. The cubic root of 139172779 is about 518.2246892247.

The spelling of 139172779 in words is "one hundred thirty-nine million, one hundred seventy-two thousand, seven hundred seventy-nine".