999978000520 has 32 divisors (see below), whose sum is σ = 2368368950400. Its totient is φ = 378939031488.

The previous prime is 999978000433. The next prime is 999978000521. The reversal of 999978000520 is 25000879999.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (999978000521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 657879504 + ... + 657881023.

It is an arithmetic number, because the mean of its divisors is an integer number (74011529700).

Almost surely, 2^999978000520 is an apocalyptic number.

It is an amenable number.

999978000520 is an abundant number, since it is smaller than the sum of its proper divisors (1368390949880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999978000520 is a wasteful number, since it uses less digits than its factorization.

999978000520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1315760557 (or 1315760553 counting only the distinct ones).

The product of its (nonzero) digits is 3674160, while the sum is 58.

The spelling of 999978000520 in words is "nine hundred ninety-nine billion, nine hundred seventy-eight million, five hundred twenty", and thus it is an aban number.