999999999550 has 48 divisors (see below), whose sum is σ = 1941378324192. Its totient is φ = 382508403200.

The previous prime is 999999999529. The next prime is 999999999571. The reversal of 999999999550 is 55999999999.

999999999550 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (999999999529) and next prime (999999999571).

It is a nialpdrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4351122 + ... + 4575178.

It is an arithmetic number, because the mean of its divisors is an integer number (40445381754).

Almost surely, 2^999999999550 is an apocalyptic number.

999999999550 is a deficient number, since it is larger than the sum of its proper divisors (941378324642).

999999999550 is a wasteful number, since it uses less digits than its factorization.

999999999550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227973 (or 227968 counting only the distinct ones).

The product of its (nonzero) digits is 9685512225, while the sum is 91.

The spelling of 999999999550 in words is "nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, five hundred fifty".