77617440 has 240 divisors, whose sum is σ = 281563128. Its totient is φ = 20127744.

The previous prime is 77617411. The next prime is 77617471. The reversal of 77617440 is 4471677.

It can be written as a sum of positive squares in 4 ways, for example, as 47279376 + 30338064 = 6876^2 + 5508^2 .

It is a tau number, because it is divible by the number of its divisors (240).

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 = 77617395 and 77617404.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 686824 + ... + 686936.

Almost surely, 2^77617440 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 77617440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140781564).

77617440 is an abundant number, since it is smaller than the sum of its proper divisors (203945688).

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

77617440 is a wasteful number, since it uses less digits than its factorization.

77617440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193 (or 176 counting only the distinct ones).

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

The square root of 77617440 is about 8810.0760496150. The cubic root of 77617440 is about 426.5661981324.

The spelling of 77617440 in words is "seventy-seven million, six hundred seventeen thousand, four hundred forty".