78138756 has 30 divisors (see below), whose sum is σ = 204270990. Its totient is φ = 26046144.

The previous prime is 78138727. The next prime is 78138757. The reversal of 78138756 is 65783187.

It can be written as a sum of positive squares in only one way, i.e., 77158656 + 980100 = 8784^2 + 990^2 .

It is a super-2 number, since 2×78138756² = 12211330378455072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78138757) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 120261 + ... + 120908.

It is an arithmetic number, because the mean of its divisors is an integer number (6809033).

Almost surely, 2^78138756 is an apocalyptic number.

It is an amenable number.

78138756 is an abundant number, since it is smaller than the sum of its proper divisors (126132234).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78138756 is a wasteful number, since it uses less digits than its factorization.

78138756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241185 (or 241174 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 78138756 is about 8839.6128874516. The cubic root of 78138756 is about 427.5190757878.

The spelling of 78138756 in words is "seventy-eight million, one hundred thirty-eight thousand, seven hundred fifty-six".