77016145781 has 2 divisors, whose sum is σ = 77016145782. Its totient is φ = 77016145780.

The previous prime is 77016145757. The next prime is 77016145799. The reversal of 77016145781 is 18754161077.

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., 76278154225 + 737991556 = 276185^2 + 27166^2 .

It is a cyclic number.

It is not a de Polignac number, because 77016145781 - 2²² = 77011951477 is a prime.

It is a super-2 number, since 2×77016145781² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77016145711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38508072890 + 38508072891.

It is an arithmetic number, because the mean of its divisors is an integer number (38508072891).

Almost surely, 2^77016145781 is an apocalyptic number.

It is an amenable number.

77016145781 is a deficient number, since it is larger than the sum of its proper divisors (1).

77016145781 is an equidigital number, since it uses as much as digits as its factorization.

77016145781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 329280, while the sum is 47.

The spelling of 77016145781 in words is "seventy-seven billion, sixteen million, one hundred forty-five thousand, seven hundred eighty-one".