78203857 has 2 divisors, whose sum is σ = 78203858. Its totient is φ = 78203856.

The previous prime is 78203843. The next prime is 78203861. The reversal of 78203857 is 75830287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77422401 + 781456 = 8799^2 + 884^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78203857 is a prime.

It is a super-2 number, since 2×78203857² = 12231686499352898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78203837) 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, 39101928 + 39101929.

It is an arithmetic number, because the mean of its divisors is an integer number (39101929).

Almost surely, 2^78203857 is an apocalyptic number.

It is an amenable number.

78203857 is a deficient number, since it is larger than the sum of its proper divisors (1).

78203857 is an equidigital number, since it uses as much as digits as its factorization.

78203857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 94080, while the sum is 40.

The square root of 78203857 is about 8843.2944652997. The cubic root of 78203857 is about 427.6377714475.

The spelling of 78203857 in words is "seventy-eight million, two hundred three thousand, eight hundred fifty-seven".