77611813 has 4 divisors (see below), whose sum is σ = 77738220. Its totient is φ = 77485408.

The previous prime is 77611763. The next prime is 77611837. The reversal of 77611813 is 31811677.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15233409 + 62378404 = 3903^2 + 7898^2 .

It is a cyclic number.

It is not a de Polignac number, because 77611813 - 2²⁵ = 44057381 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 (77611213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62278 + ... + 63511.

It is an arithmetic number, because the mean of its divisors is an integer number (19434555).

Almost surely, 2^77611813 is an apocalyptic number.

It is an amenable number.

77611813 is a deficient number, since it is larger than the sum of its proper divisors (126407).

77611813 is a wasteful number, since it uses less digits than its factorization.

77611813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126406.

The product of its digits is 7056, while the sum is 34.

The square root of 77611813 is about 8809.7566935756. The cubic root of 77611813 is about 426.5558896845. Note that the first 3 decimals are identical.

The spelling of 77611813 in words is "seventy-seven million, six hundred eleven thousand, eight hundred thirteen".