77761 has 2 divisors, whose sum is σ = 77762. Its totient is φ = 77760.

The previous prime is 77747. The next prime is 77773. The reversal of 77761 is 16777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59536 + 18225 = 244^2 + 135^2 .

It is a cyclic number.

It is not a de Polignac number, because 77761 - 2⁹ = 77249 is a prime.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (77711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38880 + 38881.

It is an arithmetic number, because the mean of its divisors is an integer number (38881).

2⁷⁷⁷⁶¹ is an apocalyptic number.

It is an amenable number.

77761 is a deficient number, since it is larger than the sum of its proper divisors (1).

77761 is an equidigital number, since it uses as much as digits as its factorization.

77761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2058, while the sum is 28.

The square root of 77761 is about 278.8565939690. The cubic root of 77761 is about 42.6829026209.

It can be divided in two parts, 7776 and 1, that added together give a palindrome (7777).

The spelling of 77761 in words is "seventy-seven thousand, seven hundred sixty-one".