77655551 has 2 divisors, whose sum is σ = 77655552. Its totient is φ = 77655550.

The previous prime is 77655493. The next prime is 77655569. The reversal of 77655551 is 15555677.

It is a strong prime.

It is an emirp because it is prime and its reverse (15555677) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77655551 - 2¹⁴ = 77639167 is a prime.

It is a super-2 number, since 2×77655551² = 12060769202227202, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 77655499 and 77655508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77657551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38827775 + 38827776.

It is an arithmetic number, because the mean of its divisors is an integer number (38827776).

Almost surely, 2^77655551 is an apocalyptic number.

77655551 is a deficient number, since it is larger than the sum of its proper divisors (1).

77655551 is an equidigital number, since it uses as much as digits as its factorization.

77655551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 183750, while the sum is 41.

The square root of 77655551 is about 8812.2387053461. The cubic root of 77655551 is about 426.6360029097.

The spelling of 77655551 in words is "seventy-seven million, six hundred fifty-five thousand, five hundred fifty-one".