77730840 has 192 divisors, whose sum is σ = 286191360. Its totient is φ = 18817920.

The previous prime is 77730839. The next prime is 77730841. The reversal of 77730840 is 4803777.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (77730839) and next prime (77730841).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 77730795 and 77730804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77730841) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 106557 + ... + 107283.

It is an arithmetic number, because the mean of its divisors is an integer number (1490580).

Almost surely, 2^77730840 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 77730840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143095680).

77730840 is an abundant number, since it is smaller than the sum of its proper divisors (208460520).

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

77730840 is a wasteful number, since it uses less digits than its factorization.

77730840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764 (or 748 counting only the distinct ones).

The product of its (nonzero) digits is 32928, while the sum is 36.

The square root of 77730840 is about 8816.5095134072. The cubic root of 77730840 is about 426.7738364687.

The spelling of 77730840 in words is "seventy-seven million, seven hundred thirty thousand, eight hundred forty".