77864840 has 16 divisors (see below), whose sum is σ = 175195980. Its totient is φ = 31145920.

The previous prime is 77864833. The next prime is 77864851. The reversal of 77864840 is 4846877.

It can be written as a sum of positive squares in 2 ways, for example, as 73856836 + 4008004 = 8594^2 + 2002^2 .

It is a junction number, because it is equal to n+sod(n) for n = 77864791 and 77864800.

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 3 ways as a sum of consecutive naturals, for example, 973271 + ... + 973350.

Almost surely, 2^77864840 is an apocalyptic number.

It is an amenable number.

77864840 is an abundant number, since it is smaller than the sum of its proper divisors (97331140).

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

77864840 is a wasteful number, since it uses less digits than its factorization.

77864840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1946632 (or 1946628 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 44.

The square root of 77864840 is about 8824.1056204014. The cubic root of 77864840 is about 427.0189337969.

It can be divided in two parts, 778648 and 40, that added together give a cube (778688 = 92³).

The spelling of 77864840 in words is "seventy-seven million, eight hundred sixty-four thousand, eight hundred forty".