77810042 has 8 divisors (see below), whose sum is σ = 118917396. Its totient is φ = 38170912.

The previous prime is 77810021. The next prime is 77810053. The reversal of 77810042 is 24001877.

It is a Cunningham number, because it is equal to 8821²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 77810041 + 1 = 8821^2 + 1^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 77809987 and 77810014.

It is an unprimeable number.

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, 366923 + ... + 367134.

Almost surely, 2^77810042 is an apocalyptic number.

77810042 is a deficient number, since it is larger than the sum of its proper divisors (41107354).

77810042 is a wasteful number, since it uses less digits than its factorization.

77810042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 734112.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 77810042 is about 8821.0000566829. Note that the first 4 decimals coincide. The cubic root of 77810042 is about 426.9187376324.

The spelling of 77810042 in words is "seventy-seven million, eight hundred ten thousand, forty-two".