77552640 has 440 divisors, whose sum is σ = 321002352. Its totient is φ = 17694720.

The previous prime is 77552639. The next prime is 77552663. The reversal of 77552640 is 4625577.

77552640 is a `hidden beast` number, since 7 + 7 + 5 + 5 + 2 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (440).

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 = 77552595 and 77552604.

It is a congruent number.

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 4561912 + ... + 4561928.

Almost surely, 2^77552640 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 77552640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160501176).

77552640 is an abundant number, since it is smaller than the sum of its proper divisors (243449712).

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

77552640 is a wasteful number, since it uses less digits than its factorization.

77552640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 58800, while the sum is 36.

The square root of 77552640 is about 8806.3976744183. The cubic root of 77552640 is about 426.4474568396.

The spelling of 77552640 in words is "seventy-seven million, five hundred fifty-two thousand, six hundred forty".