78457775 has 12 divisors (see below), whose sum is σ = 106132344. Its totient is φ = 57060000.

The previous prime is 78457739. The next prime is 78457837. The reversal of 78457775 is 57775487.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-78457775 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 142376 + ... + 142925.

It is an arithmetic number, because the mean of its divisors is an integer number (8844362).

Almost surely, 2^78457775 is an apocalyptic number.

78457775 is a deficient number, since it is larger than the sum of its proper divisors (27674569).

78457775 is a wasteful number, since it uses less digits than its factorization.

78457775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285322 (or 285317 counting only the distinct ones).

The product of its digits is 1920800, while the sum is 50.

The square root of 78457775 is about 8857.6393582037. The cubic root of 78457775 is about 428.1000999602.

The spelling of 78457775 in words is "seventy-eight million, four hundred fifty-seven thousand, seven hundred seventy-five".