78097681 has 2 divisors, whose sum is σ = 78097682. Its totient is φ = 78097680.

The previous prime is 78097601. The next prime is 78097687. The reversal of 78097681 is 18679087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67502656 + 10595025 = 8216^2 + 3255^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78097681 is a prime.

It is a super-2 number, since 2×78097681² = 12198495555155522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78097687) 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, 39048840 + 39048841.

It is an arithmetic number, because the mean of its divisors is an integer number (39048841).

Almost surely, 2^78097681 is an apocalyptic number.

It is an amenable number.

78097681 is a deficient number, since it is larger than the sum of its proper divisors (1).

78097681 is an equidigital number, since it uses as much as digits as its factorization.

78097681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 169344, while the sum is 46.

The square root of 78097681 is about 8837.2892336960. The cubic root of 78097681 is about 427.4441517048. Note that the first 3 decimals are identical.

The spelling of 78097681 in words is "seventy-eight million, ninety-seven thousand, six hundred eighty-one".