77000221 has 2 divisors, whose sum is σ = 77000222. Its totient is φ = 77000220.

The previous prime is 77000207. The next prime is 77000233. The reversal of 77000221 is 12200077.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39312900 + 37687321 = 6270^2 + 6139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77000221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77000201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38500110 + 38500111.

It is an arithmetic number, because the mean of its divisors is an integer number (38500111).

Almost surely, 2^77000221 is an apocalyptic number.

It is an amenable number.

77000221 is a deficient number, since it is larger than the sum of its proper divisors (1).

77000221 is an equidigital number, since it uses as much as digits as its factorization.

77000221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 196, while the sum is 19.

The square root of 77000221 is about 8774.9769800268. The cubic root of 77000221 is about 425.4324935262.

Adding to 77000221 its reverse (12200077), we get a palindrome (89200298).

The spelling of 77000221 in words is "seventy-seven million, two hundred twenty-one", and thus it is an aban number.