78156679828 has 6 divisors (see below), whose sum is σ = 136774189706. Its totient is φ = 39078339912.

The previous prime is 78156679823. The next prime is 78156679829. The reversal of 78156679828 is 82897665187.

It can be written as a sum of positive squares in only one way, i.e., 60792819844 + 17363859984 = 246562^2 + 131772^2 .

It is a super-2 number, since 2×78156679828² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78156679823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9769584975 + ... + 9769584982.

Almost surely, 2^78156679828 is an apocalyptic number.

It is an amenable number.

78156679828 is a deficient number, since it is larger than the sum of its proper divisors (58617509878).

78156679828 is a wasteful number, since it uses less digits than its factorization.

78156679828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19539169961 (or 19539169959 counting only the distinct ones).

The product of its digits is 81285120, while the sum is 67.

The spelling of 78156679828 in words is "seventy-eight billion, one hundred fifty-six million, six hundred seventy-nine thousand, eight hundred twenty-eight".