87777777 has 8 divisors (see below), whose sum is σ = 123196960. Its totient is φ = 55438560.

The previous prime is 87777773. The next prime is 87777799. The reversal of 87777777 is 77777778.

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

It is not a de Polignac number, because 87777777 - 2² = 87777773 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 1539961 = 87777777 / (8 + 7 + 7 + 7 + 7 + 7 + 7 + 7).

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (87777773) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 769924 + ... + 770037.

It is an arithmetic number, because the mean of its divisors is an integer number (15399620).

Almost surely, 2^87777777 is an apocalyptic number.

It is an amenable number.

87777777 is a deficient number, since it is larger than the sum of its proper divisors (35419183).

87777777 is a wasteful number, since it uses less digits than its factorization.

87777777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1539983.

The product of its digits is 6588344, while the sum is 57.

The square root of 87777777 is about 9368.9795068620. The cubic root of 87777777 is about 444.4212937779.

Subtracting from 87777777 its reverse (77777778), we obtain a palindrome (9999999).

The spelling of 87777777 in words is "eighty-seven million, seven hundred seventy-seven thousand, seven hundred seventy-seven".