78138152 has 8 divisors (see below), whose sum is σ = 146509050. Its totient is φ = 39069072.

The previous prime is 78138149. The next prime is 78138157. The reversal of 78138152 is 25183187.

It can be written as a sum of positive squares in only one way, i.e., 78039556 + 98596 = 8834^2 + 314^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×78138152² = 12211141595950208, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78138157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4883627 + ... + 4883642.

Almost surely, 2^78138152 is an apocalyptic number.

It is an amenable number.

78138152 is a deficient number, since it is larger than the sum of its proper divisors (68370898).

78138152 is a wasteful number, since it uses less digits than its factorization.

78138152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9767275 (or 9767271 counting only the distinct ones).

The product of its digits is 13440, while the sum is 35.

The square root of 78138152 is about 8839.5787229935. The cubic root of 78138152 is about 427.5179742337.

The spelling of 78138152 in words is "seventy-eight million, one hundred thirty-eight thousand, one hundred fifty-two".