78866461 has 2 divisors, whose sum is σ = 78866462. Its totient is φ = 78866460.

The previous prime is 78866453. The next prime is 78866479. The reversal of 78866461 is 16466887.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46308025 + 32558436 = 6805^2 + 5706^2 .

It is a cyclic number.

It is not a de Polignac number, because 78866461 - 2³ = 78866453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78866441) 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, 39433230 + 39433231.

It is an arithmetic number, because the mean of its divisors is an integer number (39433231).

Almost surely, 2^78866461 is an apocalyptic number.

It is an amenable number.

78866461 is a deficient number, since it is larger than the sum of its proper divisors (1).

78866461 is an equidigital number, since it uses as much as digits as its factorization.

78866461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 46.

The square root of 78866461 is about 8880.6790843944. The cubic root of 78866461 is about 428.8421364999.

The spelling of 78866461 in words is "seventy-eight million, eight hundred sixty-six thousand, four hundred sixty-one".