78457251 has 8 divisors (see below), whose sum is σ = 110115520. Its totient is φ = 49551912.

The previous prime is 78457237. The next prime is 78457259. The reversal of 78457251 is 15275487.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78457251 - 2⁷ = 78457123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78457259) 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 7 ways as a sum of consecutive naturals, for example, 688165 + ... + 688278.

It is an arithmetic number, because the mean of its divisors is an integer number (13764440).

Almost surely, 2^78457251 is an apocalyptic number.

78457251 is a deficient number, since it is larger than the sum of its proper divisors (31658269).

78457251 is a wasteful number, since it uses less digits than its factorization.

78457251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1376465.

The product of its digits is 78400, while the sum is 39.

The square root of 78457251 is about 8857.6097791673. The cubic root of 78457251 is about 428.0991469000.

The spelling of 78457251 in words is "seventy-eight million, four hundred fifty-seven thousand, two hundred fifty-one".