77720801 has 2 divisors, whose sum is σ = 77720802. Its totient is φ = 77720800.

The previous prime is 77720791. The next prime is 77720807. The reversal of 77720801 is 10802777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58369600 + 19351201 = 7640^2 + 4399^2 .

It is an emirp because it is prime and its reverse (10802777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77720801 - 2¹⁰ = 77719777 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77720807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38860400 + 38860401.

It is an arithmetic number, because the mean of its divisors is an integer number (38860401).

Almost surely, 2^77720801 is an apocalyptic number.

It is an amenable number.

77720801 is a deficient number, since it is larger than the sum of its proper divisors (1).

77720801 is an equidigital number, since it uses as much as digits as its factorization.

77720801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5488, while the sum is 32.

The square root of 77720801 is about 8815.9401654049. The cubic root of 77720801 is about 426.7554629505.

The spelling of 77720801 in words is "seventy-seven million, seven hundred twenty thousand, eight hundred one".