77845509 has 32 divisors (see below), whose sum is σ = 132464640. Its totient is φ = 44259696.

The previous prime is 77845487. The next prime is 77845519. The reversal of 77845509 is 90554877.

It is not a de Polignac number, because 77845509 - 2⁸ = 77845253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77845519) 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 31 ways as a sum of consecutive naturals, for example, 41224 + ... + 43070.

It is an arithmetic number, because the mean of its divisors is an integer number (4139520).

Almost surely, 2^77845509 is an apocalyptic number.

It is an amenable number.

77845509 is a deficient number, since it is larger than the sum of its proper divisors (54619131).

77845509 is a wasteful number, since it uses less digits than its factorization.

77845509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2086 (or 2080 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 45.

The square root of 77845509 is about 8823.0102006061. The cubic root of 77845509 is about 426.9835931296.

The spelling of 77845509 in words is "seventy-seven million, eight hundred forty-five thousand, five hundred nine".