77818722408 has 864 divisors, whose sum is σ = 280785173760. Its totient is φ = 20105003520.

The previous prime is 77818722403. The next prime is 77818722413. The reversal of 77818722408 is 80422781877.

It is an interprime number because it is at equal distance from previous prime (77818722403) and next prime (77818722413).

It is a super-2 number, since 2×77818722408² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (77818722403) by changing a digit.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 1066009860 + ... + 1066009932.

It is an arithmetic number, because the mean of its divisors is an integer number (324982840).

Almost surely, 2^77818722408 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 77818722408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140392586880).

77818722408 is an abundant number, since it is smaller than the sum of its proper divisors (202966451352).

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

77818722408 is a wasteful number, since it uses less digits than its factorization.

77818722408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 2809856, while the sum is 54.

The spelling of 77818722408 in words is "seventy-seven billion, eight hundred eighteen million, seven hundred twenty-two thousand, four hundred eight".