77727979 has 8 divisors (see below), whose sum is σ = 89365248. Its totient is φ = 66224040.

The previous prime is 77727959. The next prime is 77727983. The reversal of 77727979 is 97972777.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77727979 - 2¹³ = 77719787 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77727959) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 32077 + ... + 34414.

It is an arithmetic number, because the mean of its divisors is an integer number (11170656).

Almost surely, 2^77727979 is an apocalyptic number.

77727979 is a deficient number, since it is larger than the sum of its proper divisors (11637269).

77727979 is a wasteful number, since it uses less digits than its factorization.

77727979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66665.

The product of its digits is 2722734, while the sum is 55.

The square root of 77727979 is about 8816.3472594947. The cubic root of 77727979 is about 426.7686003877.

It can be divided in two parts, 7772 and 7979, that added together give a palindrome (15751).

The spelling of 77727979 in words is "seventy-seven million, seven hundred twenty-seven thousand, nine hundred seventy-nine".