77855117 has 2 divisors, whose sum is σ = 77855118. Its totient is φ = 77855116.

The previous prime is 77855059. The next prime is 77855131. The reversal of 77855117 is 71155877.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48846121 + 29008996 = 6989^2 + 5386^2 .

It is a cyclic number.

It is not a de Polignac number, because 77855117 - 2¹⁰ = 77854093 is a prime.

It is a super-2 number, since 2×77855117² = 12122838486167378, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77855417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38927558 + 38927559.

It is an arithmetic number, because the mean of its divisors is an integer number (38927559).

Almost surely, 2^77855117 is an apocalyptic number.

It is an amenable number.

77855117 is a deficient number, since it is larger than the sum of its proper divisors (1).

77855117 is an equidigital number, since it uses as much as digits as its factorization.

77855117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68600, while the sum is 41.

The square root of 77855117 is about 8823.5546691795. The cubic root of 77855117 is about 427.0011590738.

The spelling of 77855117 in words is "seventy-seven million, eight hundred fifty-five thousand, one hundred seventeen".