78257138 has 16 divisors (see below), whose sum is σ = 121673880. Its totient is φ = 37704576.

The previous prime is 78257111. The next prime is 78257147. The reversal of 78257138 is 83175287.

It can be written as a sum of positive squares in 4 ways, for example, as 77563249 + 693889 = 8807^2 + 833^2 .

It is a super-2 number, since 2×78257138² = 12248359295902088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78257095 and 78257104.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38270 + ... + 40262.

Almost surely, 2^78257138 is an apocalyptic number.

78257138 is a deficient number, since it is larger than the sum of its proper divisors (43416742).

78257138 is a wasteful number, since it uses less digits than its factorization.

78257138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2701.

The product of its digits is 94080, while the sum is 41.

The square root of 78257138 is about 8846.3064608909. The cubic root of 78257138 is about 427.7348672362.

The spelling of 78257138 in words is "seventy-eight million, two hundred fifty-seven thousand, one hundred thirty-eight".