77820012 has 36 divisors (see below), whose sum is σ = 198272256. Its totient is φ = 25734240.

The previous prime is 77820007. The next prime is 77820019. The reversal of 77820012 is 21002877.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (77820019) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3939 + ... + 13082.

Almost surely, 2^77820012 is an apocalyptic number.

It is an amenable number.

77820012 is an abundant number, since it is smaller than the sum of its proper divisors (120452244).

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

77820012 is a wasteful number, since it uses less digits than its factorization.

77820012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17158 (or 17153 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 77820012 is about 8821.5651672478. The cubic root of 77820012 is about 426.9369709175.

Adding to 77820012 its reverse (21002877), we get a palindrome (98822889).

The spelling of 77820012 in words is "seventy-seven million, eight hundred twenty thousand, twelve".