77904853255661 has 2 divisors, whose sum is σ = 77904853255662. Its totient is φ = 77904853255660.

The previous prime is 77904853255627. The next prime is 77904853255703. The reversal of 77904853255661 is 16655235840977.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71447613223561 + 6457240032100 = 8452669^2 + 2541110^2 .

It is a cyclic number.

It is not a de Polignac number, because 77904853255661 - 2¹⁰ = 77904853254637 is a prime.

It is a super-2 number, since 2×77904853255661² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 77904853255591 and 77904853255600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77934853255661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38952426627830 + 38952426627831.

It is an arithmetic number, because the mean of its divisors is an integer number (38952426627831).

It is a 1-persistent number, because it is pandigital, but 2⋅77904853255661 = 155809706511322 is not.

Almost surely, 2^{77904853255661} is an apocalyptic number.

It is an amenable number.

77904853255661 is a deficient number, since it is larger than the sum of its proper divisors (1).

77904853255661 is an equidigital number, since it uses as much as digits as its factorization.

77904853255661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 381024000, while the sum is 68.

The spelling of 77904853255661 in words is "seventy-seven trillion, nine hundred four billion, eight hundred fifty-three million, two hundred fifty-five thousand, six hundred sixty-one".