172221776777 has 2 divisors, whose sum is σ = 172221776778. Its totient is φ = 172221776776.

The previous prime is 172221776773. The next prime is 172221776803. The reversal of 172221776777 is 777677122271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136217093776 + 36004683001 = 369076^2 + 189749^2 .

It is a cyclic number.

It is not a de Polignac number, because 172221776777 - 2² = 172221776773 is a prime.

It is not a weakly prime, because it can be changed into another prime (172221776773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86110888388 + 86110888389.

It is an arithmetic number, because the mean of its divisors is an integer number (86110888389).

Almost surely, 2^172221776777 is an apocalyptic number.

It is an amenable number.

172221776777 is a deficient number, since it is larger than the sum of its proper divisors (1).

172221776777 is an equidigital number, since it uses as much as digits as its factorization.

172221776777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5647152, while the sum is 56.

The spelling of 172221776777 in words is "one hundred seventy-two billion, two hundred twenty-one million, seven hundred seventy-six thousand, seven hundred seventy-seven".