77822566668 has 396 divisors, whose sum is σ = 257279764560. Its totient is φ = 20161690560.

The previous prime is 77822566667. The next prime is 77822566669. The reversal of 77822566668 is 86666522877.

It is an interprime number because it is at equal distance from previous prime (77822566667) and next prime (77822566669).

It is a tau number, because it is divible by the number of its divisors (396).

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

It is not an unprimeable number, because it can be changed into a prime (77822566667) by changing a digit.

It is a polite number, since it can be written in 131 ways as a sum of consecutive naturals, for example, 200057818 + ... + 200058206.

Almost surely, 2^77822566668 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 77822566668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128639882280).

77822566668 is an abundant number, since it is smaller than the sum of its proper divisors (179457197892).

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

77822566668 is a wasteful number, since it uses less digits than its factorization.

77822566668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452 (or 412 counting only the distinct ones).

The product of its digits is 81285120, while the sum is 63.

The spelling of 77822566668 in words is "seventy-seven billion, eight hundred twenty-two million, five hundred sixty-six thousand, six hundred sixty-eight".