78115738 has 4 divisors (see below), whose sum is σ = 117173610. Its totient is φ = 39057868.

The previous prime is 78115729. The next prime is 78115801. The reversal of 78115738 is 83751187.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83751187 = 13 ⋅6442399.

It can be written as a sum of positive squares in only one way, i.e., 77915929 + 199809 = 8827^2 + 447^2 .

It is a super-2 number, since 2×78115738² = 12204137046569288, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78115738.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19528933 + ... + 19528936.

Almost surely, 2^78115738 is an apocalyptic number.

78115738 is a deficient number, since it is larger than the sum of its proper divisors (39057872).

78115738 is a wasteful number, since it uses less digits than its factorization.

78115738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39057871.

The product of its digits is 47040, while the sum is 40.

The square root of 78115738 is about 8838.3108114617. The cubic root of 78115738 is about 427.4770923512.

The spelling of 78115738 in words is "seventy-eight million, one hundred fifteen thousand, seven hundred thirty-eight".