77420840646 has 32 divisors (see below), whose sum is σ = 155238453216. Its totient is φ = 25740864000.

The previous prime is 77420840617. The next prime is 77420840699. The reversal of 77420840646 is 64604802477.

It is a junction number, because it is equal to n+sod(n) for n = 77420840595 and 77420840604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11118606 + ... + 11125566.

It is an arithmetic number, because the mean of its divisors is an integer number (4851201663).

Almost surely, 2^77420840646 is an apocalyptic number.

77420840646 is an abundant number, since it is smaller than the sum of its proper divisors (77817612570).

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

77420840646 is a wasteful number, since it uses less digits than its factorization.

77420840646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11448.

The product of its (nonzero) digits is 1806336, while the sum is 48.

The spelling of 77420840646 in words is "seventy-seven billion, four hundred twenty million, eight hundred forty thousand, six hundred forty-six".