77690509 has 4 divisors (see below), whose sum is σ = 83666716. Its totient is φ = 71714304.

The previous prime is 77690497. The next prime is 77690519. The reversal of 77690509 is 90509677.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90509677 = 31 ⋅2919667.

It can be written as a sum of positive squares in 2 ways, for example, as 7717284 + 69973225 = 2778^2 + 8365^2 .

It is a cyclic number.

It is not a de Polignac number, because 77690509 - 2⁷ = 77690381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77690519) 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 3 ways as a sum of consecutive naturals, for example, 2988084 + ... + 2988109.

It is an arithmetic number, because the mean of its divisors is an integer number (20916679).

Almost surely, 2^77690509 is an apocalyptic number.

It is an amenable number.

77690509 is a deficient number, since it is larger than the sum of its proper divisors (5976207).

77690509 is a wasteful number, since it uses less digits than its factorization.

77690509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5976206.

The product of its (nonzero) digits is 119070, while the sum is 43.

The square root of 77690509 is about 8814.2219736061. The cubic root of 77690509 is about 426.7000125170.

The spelling of 77690509 in words is "seventy-seven million, six hundred ninety thousand, five hundred nine".