78147821808 has 60 divisors (see below), whose sum is σ = 249948988848. Its totient is φ = 22327948800.

The previous prime is 78147821803. The next prime is 78147821831. The reversal of 78147821808 is 80812874187.

It is a happy number.

78147821808 is a `hidden beast` number, since 78 + 1 + 478 + 21 + 80 + 8 = 666.

It is a super-2 number, since 2×78147821808² (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 (78147821803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38762793 + ... + 38764808.

Almost surely, 2^78147821808 is an apocalyptic number.

It is an amenable number.

78147821808 is an abundant number, since it is smaller than the sum of its proper divisors (171801167040).

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

78147821808 is a wasteful number, since it uses less digits than its factorization.

78147821808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77527622 (or 77527613 counting only the distinct ones).

The product of its (nonzero) digits is 1605632, while the sum is 54.

The spelling of 78147821808 in words is "seventy-eight billion, one hundred forty-seven million, eight hundred twenty-one thousand, eight hundred eight".