999978000122 has 8 divisors (see below), whose sum is σ = 1499981345076. Its totient is φ = 499984218432.

The previous prime is 999978000113. The next prime is 999978000139. The reversal of 999978000122 is 221000879999.

It is a happy number.

It is a Cunningham number, because it is equal to 999989²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 999978000121 + 1 = 999989^2 + 1^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2123423 + ... + 2551250.

Almost surely, 2^999978000122 is an apocalyptic number.

999978000122 is a deficient number, since it is larger than the sum of its proper divisors (500003344954).

999978000122 is a wasteful number, since it uses less digits than its factorization.

999978000122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4781632.

The product of its (nonzero) digits is 1469664, while the sum is 56.

The spelling of 999978000122 in words is "nine hundred ninety-nine billion, nine hundred seventy-eight million, one hundred twenty-two", and thus it is an aban number.