78693961 has 2 divisors, whose sum is σ = 78693962. Its totient is φ = 78693960.

The previous prime is 78693947. The next prime is 78693973. The reversal of 78693961 is 16939687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78428736 + 265225 = 8856^2 + 515^2 .

It is an emirp because it is prime and its reverse (16939687) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78693961 - 2⁵ = 78693929 is a prime.

It is not a weakly prime, because it can be changed into another prime (78693911) 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, 39346980 + 39346981.

It is an arithmetic number, because the mean of its divisors is an integer number (39346981).

Almost surely, 2^78693961 is an apocalyptic number.

It is an amenable number.

78693961 is a deficient number, since it is larger than the sum of its proper divisors (1).

78693961 is an equidigital number, since it uses as much as digits as its factorization.

78693961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 49.

The square root of 78693961 is about 8870.9616727838. The cubic root of 78693961 is about 428.5292478222.

It can be divided in two parts, 7 and 8693961, that added together give a palindrome (8693968).

The spelling of 78693961 in words is "seventy-eight million, six hundred ninety-three thousand, nine hundred sixty-one".