77946689 has 4 divisors (see below), whose sum is σ = 77971140. Its totient is φ = 77922240.

The previous prime is 77946667. The next prime is 77946697. The reversal of 77946689 is 98664977.

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

It can be written as a sum of positive squares in 2 ways, for example, as 34281025 + 43665664 = 5855^2 + 6608^2 .

It is a cyclic number.

It is not a de Polignac number, because 77946689 - 2⁸ = 77946433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77946629) 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, 6572 + ... + 14109.

It is an arithmetic number, because the mean of its divisors is an integer number (19492785).

Almost surely, 2^77946689 is an apocalyptic number.

It is an amenable number.

77946689 is a deficient number, since it is larger than the sum of its proper divisors (24451).

77946689 is a wasteful number, since it uses less digits than its factorization.

77946689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24450.

The product of its digits is 4572288, while the sum is 56.

The square root of 77946689 is about 8828.7422093977. The cubic root of 77946689 is about 427.1685042294.

The spelling of 77946689 in words is "seventy-seven million, nine hundred forty-six thousand, six hundred eighty-nine".