78375457 has 4 divisors (see below), whose sum is σ = 82985796. Its totient is φ = 73765120.

The previous prime is 78375403. The next prime is 78375497. The reversal of 78375457 is 75457387.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 40908816 + 37466641 = 6396^2 + 6121^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78375457 is a prime.

It is a super-2 number, since 2×78375457² = 12285424519917698, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78375497) 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 3 ways as a sum of consecutive naturals, for example, 2305144 + ... + 2305177.

It is an arithmetic number, because the mean of its divisors is an integer number (20746449).

Almost surely, 2^78375457 is an apocalyptic number.

It is an amenable number.

78375457 is a deficient number, since it is larger than the sum of its proper divisors (4610339).

78375457 is a wasteful number, since it uses less digits than its factorization.

78375457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4610338.

The product of its digits is 823200, while the sum is 46.

The square root of 78375457 is about 8852.9914153353. The cubic root of 78375457 is about 427.9503265058.

The spelling of 78375457 in words is "seventy-eight million, three hundred seventy-five thousand, four hundred fifty-seven".