999416889781 has 2 divisors, whose sum is σ = 999416889782. Its totient is φ = 999416889780.

The previous prime is 999416889769. The next prime is 999416889829. The reversal of 999416889781 is 187988614999.

999416889781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 544917094225 + 454499795556 = 738185^2 + 674166^2 .

It is a cyclic number.

It is not a de Polignac number, because 999416889781 - 2⁹ = 999416889269 is a prime.

It is a super-2 number, since 2×999416889781² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999416889881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499708444890 + 499708444891.

It is an arithmetic number, because the mean of its divisors is an integer number (499708444891).

Almost surely, 2^999416889781 is an apocalyptic number.

It is an amenable number.

999416889781 is a deficient number, since it is larger than the sum of its proper divisors (1).

999416889781 is an equidigital number, since it uses as much as digits as its factorization.

999416889781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 564350976, while the sum is 79.

The spelling of 999416889781 in words is "nine hundred ninety-nine billion, four hundred sixteen million, eight hundred eighty-nine thousand, seven hundred eighty-one".