77731693 has 4 divisors (see below), whose sum is σ = 83711068. Its totient is φ = 71752320.

The previous prime is 77731657. The next prime is 77731739. The reversal of 77731693 is 39613777.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39613777 = 7 ⋅5659111.

It can be written as a sum of positive squares in 2 ways, for example, as 27008809 + 50722884 = 5197^2 + 7122^2 .

It is a cyclic number.

It is not a de Polignac number, because 77731693 - 2¹³ = 77723501 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 (77731193) 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, 2989668 + ... + 2989693.

It is an arithmetic number, because the mean of its divisors is an integer number (20927767).

Almost surely, 2^77731693 is an apocalyptic number.

It is an amenable number.

77731693 is a deficient number, since it is larger than the sum of its proper divisors (5979375).

77731693 is a wasteful number, since it uses less digits than its factorization.

77731693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5979374.

The product of its digits is 166698, while the sum is 43.

The square root of 77731693 is about 8816.5578884279. The cubic root of 77731693 is about 426.7753975683.

The spelling of 77731693 in words is "seventy-seven million, seven hundred thirty-one thousand, six hundred ninety-three".