999987777 has 6 divisors (see below), whose sum is σ = 1444426802. Its totient is φ = 666658512.

The previous prime is 999987763. The next prime is 999987829. The reversal of 999987777 is 777789999.

999987777 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 959078961 + 40908816 = 30969^2 + 6396^2 .

It is not a de Polignac number, because 999987777 - 2⁴ = 999987761 is a prime.

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 (999987377) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55554868 + ... + 55554885.

Almost surely, 2^999987777 is an apocalyptic number.

It is an amenable number.

999987777 is a deficient number, since it is larger than the sum of its proper divisors (444439025).

999987777 is a wasteful number, since it uses less digits than its factorization.

999987777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111109759 (or 111109756 counting only the distinct ones).

The product of its digits is 126023688, while the sum is 72.

The square root of 999987777 is about 31622.5833384940. The cubic root of 999987777 is about 999.9959256501.

The spelling of 999987777 in words is "nine hundred ninety-nine million, nine hundred eighty-seven thousand, seven hundred seventy-seven".