999999988777 has 2 divisors, whose sum is σ = 999999988778. Its totient is φ = 999999988776.

The previous prime is 999999988769. The next prime is 999999988811. The reversal of 999999988777 is 777889999999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 941949832681 + 58050156096 = 970541^2 + 240936^2 .

It is a cyclic number.

It is not a de Polignac number, because 999999988777 - 2³ = 999999988769 is a prime.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is not a weakly prime, because it can be changed into another prime (999999988577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499999994388 + 499999994389.

It is an arithmetic number, because the mean of its divisors is an integer number (499999994389).

Almost surely, 2^999999988777 is an apocalyptic number.

It is an amenable number.

999999988777 is a deficient number, since it is larger than the sum of its proper divisors (1).

999999988777 is an equidigital number, since it uses as much as digits as its factorization.

999999988777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104995735488, while the sum is 100.

The spelling of 999999988777 in words is "nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred eighty-eight thousand, seven hundred seventy-seven".