78438775 has 6 divisors (see below), whose sum is σ = 97264112. Its totient is φ = 62751000.

The previous prime is 78438757. The next prime is 78438803. The reversal of 78438775 is 57783487.

It is not a de Polignac number, because 78438775 - 2⁹ = 78438263 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1568751 + ... + 1568800.

Almost surely, 2^78438775 is an apocalyptic number.

78438775 is a deficient number, since it is larger than the sum of its proper divisors (18825337).

78438775 is a wasteful number, since it uses less digits than its factorization.

78438775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3137561 (or 3137556 counting only the distinct ones).

The product of its digits is 1317120, while the sum is 49.

The square root of 78438775 is about 8856.5667727399. The cubic root of 78438775 is about 428.0655397203.

The spelling of 78438775 in words is "seventy-eight million, four hundred thirty-eight thousand, seven hundred seventy-five".