77525640 has 128 divisors (see below), whose sum is σ = 269740800. Its totient is φ = 19768320.

The previous prime is 77525621. The next prime is 77525641. The reversal of 77525640 is 4652577.

77525640 is a `hidden beast` number, since 7 + 7 + 5 + 2 + 5 + 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 = 77525595 and 77525604.

It is not an unprimeable number, because it can be changed into a prime (77525641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23280 + ... + 26400.

It is an arithmetic number, because the mean of its divisors is an integer number (2107350).

Almost surely, 2^77525640 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 77525640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134870400).

77525640 is an abundant number, since it is smaller than the sum of its proper divisors (192215160).

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

77525640 is a wasteful number, since it uses less digits than its factorization.

77525640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3164 (or 3154 counting only the distinct ones).

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

The square root of 77525640 is about 8804.8645645461. The cubic root of 77525640 is about 426.3979617792.

The spelling of 77525640 in words is "seventy-seven million, five hundred twenty-five thousand, six hundred forty".