78458257 has 6 divisors (see below), whose sum is σ = 78969282. Its totient is φ = 77950512.

The previous prime is 78458249. The next prime is 78458279. The reversal of 78458257 is 75285487.

It can be written as a sum of positive squares in only one way, i.e., 74632321 + 3825936 = 8639^2 + 1956^2 .

It is not a de Polignac number, because 78458257 - 2³ = 78458249 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78458227) 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 in 5 ways as a sum of consecutive naturals, for example, 25093 + ... + 28045.

It is an arithmetic number, because the mean of its divisors is an integer number (13161547).

Almost surely, 2^78458257 is an apocalyptic number.

It is an amenable number.

78458257 is a deficient number, since it is larger than the sum of its proper divisors (511025).

78458257 is an equidigital number, since it uses as much as digits as its factorization.

78458257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3279 (or 3116 counting only the distinct ones).

The product of its digits is 627200, while the sum is 46.

The square root of 78458257 is about 8857.6665663142. Note that the first 3 decimals coincide. The cubic root of 78458257 is about 428.1009766263.

The spelling of 78458257 in words is "seventy-eight million, four hundred fifty-eight thousand, two hundred fifty-seven".