77880753781 has 2 divisors, whose sum is σ = 77880753782. Its totient is φ = 77880753780.

The previous prime is 77880753751. The next prime is 77880753791. The reversal of 77880753781 is 18735708877.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44696302225 + 33184451556 = 211415^2 + 182166^2 .

It is an emirp because it is prime and its reverse (18735708877) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77880753781 - 2¹³ = 77880745589 is a prime.

It is a super-2 number, since 2×77880753781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77880753751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38940376890 + 38940376891.

It is an arithmetic number, because the mean of its divisors is an integer number (38940376891).

Almost surely, 2^77880753781 is an apocalyptic number.

It is an amenable number.

77880753781 is a deficient number, since it is larger than the sum of its proper divisors (1).

77880753781 is an equidigital number, since it uses as much as digits as its factorization.

77880753781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18439680, while the sum is 61.

The spelling of 77880753781 in words is "seventy-seven billion, eight hundred eighty million, seven hundred fifty-three thousand, seven hundred eighty-one".