77820872 has 16 divisors (see below), whose sum is σ = 148307100. Its totient is φ = 38272320.

The previous prime is 77820859. The next prime is 77820887. The reversal of 77820872 is 27802877.

It can be written as a sum of positive squares in 2 ways, for example, as 69789316 + 8031556 = 8354^2 + 2834^2 .

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, 79247 + ... + 80222.

Almost surely, 2^77820872 is an apocalyptic number.

It is an amenable number.

77820872 is a deficient number, since it is larger than the sum of its proper divisors (70486228).

77820872 is a wasteful number, since it uses less digits than its factorization.

77820872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159536 (or 159532 counting only the distinct ones).

The product of its (nonzero) digits is 87808, while the sum is 41.

The square root of 77820872 is about 8821.6139112976. The cubic root of 77820872 is about 426.9385436254.

The spelling of 77820872 in words is "seventy-seven million, eight hundred twenty thousand, eight hundred seventy-two".