139978777 has 4 divisors (see below), whose sum is σ = 142619940. Its totient is φ = 137337616.

The previous prime is 139978771. The next prime is 139978793. The reversal of 139978777 is 777879931.

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

It can be written as a sum of positive squares in 2 ways, for example, as 128391561 + 11587216 = 11331^2 + 3404^2 .

It is a cyclic number.

It is not a de Polignac number, because 139978777 - 2¹¹ = 139976729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139978771) by changing a digit.

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, 1320502 + ... + 1320607.

It is an arithmetic number, because the mean of its divisors is an integer number (35654985).

Almost surely, 2^139978777 is an apocalyptic number.

It is an amenable number.

139978777 is a deficient number, since it is larger than the sum of its proper divisors (2641163).

139978777 is an equidigital number, since it uses as much as digits as its factorization.

139978777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2641162.

The product of its digits is 4667544, while the sum is 58.

The square root of 139978777 is about 11831.2626967708. The cubic root of 139978777 is about 519.2231706919.

The spelling of 139978777 in words is "one hundred thirty-nine million, nine hundred seventy-eight thousand, seven hundred seventy-seven".