78421722712388 has 12 divisors (see below), whose sum is σ = 149714197905552. Its totient is φ = 35646237596520.

The previous prime is 78421722712369. The next prime is 78421722712447. The reversal of 78421722712388 is 88321722712487.

It is a super-2 number, since 2×78421722712388² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78421722712388.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 891155939870 + ... + 891155939957.

It is an arithmetic number, because the mean of its divisors is an integer number (12476183158796).

Almost surely, 2^{78421722712388} is an apocalyptic number.

It is an amenable number.

78421722712388 is a deficient number, since it is larger than the sum of its proper divisors (71292475193164).

78421722712388 is a wasteful number, since it uses less digits than its factorization.

78421722712388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1782311879842 (or 1782311879840 counting only the distinct ones).

The product of its digits is 33718272, while the sum is 62.

Subtracting 78421722712388 from its reverse (88321722712487), we obtain a palindrome (9900000000099).

The spelling of 78421722712388 in words is "seventy-eight trillion, four hundred twenty-one billion, seven hundred twenty-two million, seven hundred twelve thousand, three hundred eighty-eight".