77861812 has 12 divisors (see below), whose sum is σ = 155723680. Its totient is φ = 33369336.

The previous prime is 77861783. The next prime is 77861837. The reversal of 77861812 is 21816877.

77861812 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1390362 + ... + 1390417.

Almost surely, 2^77861812 is an apocalyptic number.

It is an amenable number.

77861812 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

77861812 is a wasteful number, since it uses less digits than its factorization.

77861812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2780790 (or 2780788 counting only the distinct ones).

The product of its digits is 37632, while the sum is 40.

The square root of 77861812 is about 8823.9340432712. The cubic root of 77861812 is about 427.0133984355.

The spelling of 77861812 in words is "seventy-seven million, eight hundred sixty-one thousand, eight hundred twelve".