77606640 has 320 divisors, whose sum is σ = 295219200. Its totient is φ = 18662400.

The previous prime is 77606611. The next prime is 77606647. The reversal of 77606640 is 4660677.

77606640 is a `hidden beast` number, since 7 + 7 + 6 + 0 + 6 + 640 = 666.

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 = 77606595 and 77606604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77606647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1272210 + ... + 1272270.

It is an arithmetic number, because the mean of its divisors is an integer number (922560).

Almost surely, 2^77606640 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 77606640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147609600).

77606640 is an abundant number, since it is smaller than the sum of its proper divisors (217612560).

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

77606640 is a wasteful number, since it uses less digits than its factorization.

77606640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 36.

The square root of 77606640 is about 8809.4630937419. The cubic root of 77606640 is about 426.5464125076.

It can be divided in two parts, 7760 and 6640, that added together give a square (14400 = 120²).

The spelling of 77606640 in words is "seventy-seven million, six hundred six thousand, six hundred forty".