78187809312 has 36 divisors (see below), whose sum is σ = 222346583550. Its totient is φ = 26062603008.

The previous prime is 78187809289. The next prime is 78187809341. The reversal of 78187809312 is 21390878187.

It is a happy number.

78187809312 is a `hidden beast` number, since 78 + 187 + 80 + 9 + 312 = 666.

It can be written as a sum of positive squares in only one way, i.e., 76593883536 + 1593925776 = 276756^2 + 39924^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×78187809312² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 135742437 + ... + 135743012.

Almost surely, 2^78187809312 is an apocalyptic number.

78187809312 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

78187809312 is an abundant number, since it is smaller than the sum of its proper divisors (144158774238).

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

78187809312 is a wasteful number, since it uses less digits than its factorization.

78187809312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271485465 (or 271485454 counting only the distinct ones).

The product of its (nonzero) digits is 1354752, while the sum is 54.

The spelling of 78187809312 in words is "seventy-eight billion, one hundred eighty-seven million, eight hundred nine thousand, three hundred twelve".