78321161 has 2 divisors, whose sum is σ = 78321162. Its totient is φ = 78321160.

The previous prime is 78321151. The next prime is 78321167. The reversal of 78321161 is 16112387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78145600 + 175561 = 8840^2 + 419^2 .

It is a cyclic number.

It is not a de Polignac number, because 78321161 - 2¹⁴ = 78304777 is a prime.

It is a super-2 number, since 2×78321161² = 12268408520775842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78321167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39160580 + 39160581.

It is an arithmetic number, because the mean of its divisors is an integer number (39160581).

Almost surely, 2^78321161 is an apocalyptic number.

It is an amenable number.

78321161 is a deficient number, since it is larger than the sum of its proper divisors (1).

78321161 is an equidigital number, since it uses as much as digits as its factorization.

78321161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 29.

The square root of 78321161 is about 8849.9243499592. The cubic root of 78321161 is about 427.8514802615.

The spelling of 78321161 in words is "seventy-eight million, three hundred twenty-one thousand, one hundred sixty-one".