77820843839 has 4 divisors (see below), whose sum is σ = 77823231600. Its totient is φ = 77818456080.

The previous prime is 77820843829. The next prime is 77820843847. The reversal of 77820843839 is 93834802877.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77820843839 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 (77820843809) 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, 1144307 + ... + 1210404.

It is an arithmetic number, because the mean of its divisors is an integer number (19455807900).

Almost surely, 2^77820843839 is an apocalyptic number.

77820843839 is a deficient number, since it is larger than the sum of its proper divisors (2387761).

77820843839 is a wasteful number, since it uses less digits than its factorization.

77820843839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2387760.

The product of its (nonzero) digits is 16257024, while the sum is 59.

The spelling of 77820843839 in words is "seventy-seven billion, eight hundred twenty million, eight hundred forty-three thousand, eight hundred thirty-nine".