77820435840 has 384 divisors, whose sum is σ = 297870289920. Its totient is φ = 17213091840.

The previous prime is 77820435829. The next prime is 77820435841. The reversal of 77820435840 is 4853402877.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 77820435840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77820435841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2903139 + ... + 2929821.

It is an arithmetic number, because the mean of its divisors is an integer number (775703880).

Almost surely, 2^77820435840 is an apocalyptic number.

77820435840 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77820435840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148935144960).

77820435840 is an abundant number, since it is smaller than the sum of its proper divisors (220049854080).

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

77820435840 is a wasteful number, since it uses less digits than its factorization.

77820435840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26750 (or 26731 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 48.

The spelling of 77820435840 in words is "seventy-seven billion, eight hundred twenty million, four hundred thirty-five thousand, eight hundred forty".