77928811 has 4 divisors (see below), whose sum is σ = 77947792. Its totient is φ = 77909832.

The previous prime is 77928803. The next prime is 77928817. The reversal of 77928811 is 11882977.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 77928811 - 2³ = 77928803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77928817) by changing a digit.

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, 480 + ... + 12493.

It is an arithmetic number, because the mean of its divisors is an integer number (19486948).

Almost surely, 2^77928811 is an apocalyptic number.

77928811 is a deficient number, since it is larger than the sum of its proper divisors (18981).

77928811 is a wasteful number, since it uses less digits than its factorization.

77928811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18980.

The product of its digits is 56448, while the sum is 43.

The square root of 77928811 is about 8827.7296628295. The cubic root of 77928811 is about 427.1358430068.

The spelling of 77928811 in words is "seventy-seven million, nine hundred twenty-eight thousand, eight hundred eleven".