77865680 has 20 divisors (see below), whose sum is σ = 181037892. Its totient is φ = 31146240.

The previous prime is 77865677. The next prime is 77865691. The reversal of 77865680 is 8656877.

It can be written as a sum of positive squares in 2 ways, for example, as 28472896 + 49392784 = 5336^2 + 7028^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 486581 + ... + 486740.

Almost surely, 2^77865680 is an apocalyptic number.

It is an amenable number.

77865680 is an abundant number, since it is smaller than the sum of its proper divisors (103172212).

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

77865680 is a wasteful number, since it uses less digits than its factorization.

77865680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 973334 (or 973328 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 47.

The square root of 77865680 is about 8824.1532171648. The cubic root of 77865680 is about 427.0204693407.

It can be divided in two parts, 7 and 7865680, that added together give a palindrome (7865687).

The spelling of 77865680 in words is "seventy-seven million, eight hundred sixty-five thousand, six hundred eighty".