78138788 has 24 divisors (see below), whose sum is σ = 168299712. Its totient is φ = 30911904.

The previous prime is 78138779. The next prime is 78138871. The reversal of 78138788 is 88783187.

It is a super-2 number, since 2×78138788² = 12211340380217888, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106970 + ... + 107697.

It is an arithmetic number, because the mean of its divisors is an integer number (7012488).

Almost surely, 2^78138788 is an apocalyptic number.

It is an amenable number.

78138788 is an abundant number, since it is smaller than the sum of its proper divisors (90160924).

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

78138788 is a wasteful number, since it uses less digits than its factorization.

78138788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214691 (or 214689 counting only the distinct ones).

The product of its digits is 602112, while the sum is 50.

The square root of 78138788 is about 8839.6146974854. The cubic root of 78138788 is about 427.5191341481.

The spelling of 78138788 in words is "seventy-eight million, one hundred thirty-eight thousand, seven hundred eighty-eight".