78904993 has 2 divisors, whose sum is σ = 78904994. Its totient is φ = 78904992.

The previous prime is 78904949. The next prime is 78905009. The reversal of 78904993 is 39940987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63632529 + 15272464 = 7977^2 + 3908^2 .

It is a cyclic number.

It is not a de Polignac number, because 78904993 - 2⁹ = 78904481 is a prime.

It is not a weakly prime, because it can be changed into another prime (78904933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39452496 + 39452497.

It is an arithmetic number, because the mean of its divisors is an integer number (39452497).

Almost surely, 2^78904993 is an apocalyptic number.

It is an amenable number.

78904993 is a deficient number, since it is larger than the sum of its proper divisors (1).

78904993 is an equidigital number, since it uses as much as digits as its factorization.

78904993 is an evil number, because the sum of its binary digits is even.

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

The square root of 78904993 is about 8882.8482481691. The cubic root of 78904993 is about 428.9119653162.

It can be divided in two parts, 78904 and 993, that added together give a palindrome (79897).

The spelling of 78904993 in words is "seventy-eight million, nine hundred four thousand, nine hundred ninety-three".