77345280 has 200 divisors, whose sum is σ = 277769052. Its totient is φ = 20570112.

The previous prime is 77345267. The next prime is 77345287. The reversal of 77345280 is 8254377.

It can be written as a sum of positive squares in 2 ways, for example, as 77158656 + 186624 = 8784^2 + 432^2 .

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

It is not an unprimeable number, because it can be changed into a prime (77345287) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 207174 + ... + 207546.

Almost surely, 2^77345280 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 77345280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138884526).

77345280 is an abundant number, since it is smaller than the sum of its proper divisors (200423772).

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

77345280 is an equidigital number, since it uses as much as digits as its factorization.

77345280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408 (or 383 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 77345280 is about 8794.6165351310. The cubic root of 77345280 is about 426.0670396379.

The spelling of 77345280 in words is "seventy-seven million, three hundred forty-five thousand, two hundred eighty".