77116820 has 72 divisors (see below), whose sum is σ = 186647328. Its totient is φ = 26539200.

The previous prime is 77116807. The next prime is 77116841. The reversal of 77116820 is 2861177.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78935 + ... + 79905.

It is an arithmetic number, because the mean of its divisors is an integer number (2592324).

Almost surely, 2^77116820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77116820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93323664).

77116820 is an abundant number, since it is smaller than the sum of its proper divisors (109530508).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77116820 is a wasteful number, since it uses less digits than its factorization.

77116820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1029 (or 1008 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 32.

The square root of 77116820 is about 8781.6183018849. The cubic root of 77116820 is about 425.6471248839.

Adding to 77116820 its reverse (2861177), we get a palindrome (79977997).

The spelling of 77116820 in words is "seventy-seven million, one hundred sixteen thousand, eight hundred twenty".