78138776 has 8 divisors (see below), whose sum is σ = 146510220. Its totient is φ = 39069384.

The previous prime is 78138757. The next prime is 78138779. The reversal of 78138776 is 67783187.

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

It is a super-2 number, since 2×78138776² = 12211336629556352, 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 78138776.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78138779) by changing a digit.

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 as a sum of consecutive naturals, namely, 4883666 + ... + 4883681.

Almost surely, 2^78138776 is an apocalyptic number.

It is an amenable number.

78138776 is a deficient number, since it is larger than the sum of its proper divisors (68371444).

78138776 is a wasteful number, since it uses less digits than its factorization.

78138776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9767353 (or 9767349 counting only the distinct ones).

The product of its digits is 395136, while the sum is 47.

The square root of 78138776 is about 8839.6140187228. The cubic root of 78138776 is about 427.5191122630.

The spelling of 78138776 in words is "seventy-eight million, one hundred thirty-eight thousand, seven hundred seventy-six".