78704220409 has 2 divisors, whose sum is σ = 78704220410. Its totient is φ = 78704220408.

The previous prime is 78704220281. The next prime is 78704220443. The reversal of 78704220409 is 90402240787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68396894784 + 10307325625 = 261528^2 + 101525^2 .

It is a cyclic number.

It is not a de Polignac number, because 78704220409 - 2⁷ = 78704220281 is a prime.

It is not a weakly prime, because it can be changed into another prime (78704220449) 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, 39352110204 + 39352110205.

It is an arithmetic number, because the mean of its divisors is an integer number (39352110205).

Almost surely, 2^78704220409 is an apocalyptic number.

It is an amenable number.

78704220409 is a deficient number, since it is larger than the sum of its proper divisors (1).

78704220409 is an equidigital number, since it uses as much as digits as its factorization.

78704220409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 225792, while the sum is 43.

The spelling of 78704220409 in words is "seventy-eight billion, seven hundred four million, two hundred twenty thousand, four hundred nine".