987777777 has 16 divisors (see below), whose sum is σ = 1507684352. Its totient is φ = 563507280.

The previous prime is 987777761. The next prime is 987777793. The reversal of 987777777 is 777777789.

987777777 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (987777761) and next prime (987777793).

It is not a de Polignac number, because 987777777 - 2⁴ = 987777761 is a prime.

It is a Duffinian number.

987777777 is a modest number, since divided by 77777 gives 9877 as remainder.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (987777727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25999 + ... + 51492.

It is an arithmetic number, because the mean of its divisors is an integer number (94230272).

Almost surely, 2^987777777 is an apocalyptic number.

It is an amenable number.

987777777 is a deficient number, since it is larger than the sum of its proper divisors (519906575).

987777777 is a wasteful number, since it uses less digits than its factorization.

987777777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78108.

The product of its digits is 59295096, while the sum is 66.

The square root of 987777777 is about 31428.9321644882. The cubic root of 987777777 is about 995.9092139553.

The spelling of 987777777 in words is "nine hundred eighty-seven million, seven hundred seventy-seven thousand, seven hundred seventy-seven".