77849081856 has 768 divisors, whose sum is σ = 288833126400. Its totient is φ = 20424130560.

The previous prime is 77849081803. The next prime is 77849081857. The reversal of 77849081856 is 65818094877.

It is a tau number, because it is divible by the number of its divisors (768).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 77849081793 and 77849081802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77849081857) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 407586721 + ... + 407586911.

It is an arithmetic number, because the mean of its divisors is an integer number (376084800).

Almost surely, 2^77849081856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77849081856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144416563200).

77849081856 is an abundant number, since it is smaller than the sum of its proper divisors (210984044544).

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

77849081856 is an equidigital number, since it uses as much as digits as its factorization.

77849081856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254 (or 216 counting only the distinct ones).

The product of its (nonzero) digits is 27095040, while the sum is 63.

The spelling of 77849081856 in words is "seventy-seven billion, eight hundred forty-nine million, eighty-one thousand, eight hundred fifty-six".