999981055 has 16 divisors (see below), whose sum is σ = 1304907840.
Its totient is φ = 732575232.
The previous prime is 999981049. The next prime is 999981061. The reversal of 999981055 is 550189999.
It is an interprime number because it is at equal distance from previous prime (999981049) and next prime (999981061).
It is a cyclic number.
It is not a de Polignac number, because 999981055 - 219 = 999456767 is a prime.
It is a super-2 number, since 2×9999810552 = 1999924220717826050, which contains 22 as substring.
It is a junction number, because it is equal to n+sod(n) for n = 999980987 and 999981005.
It is a congruent number.
It is an unprimeable number.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155835 + ... + 162124.
It is an arithmetic number, because the mean of its divisors is an integer number (81556740).
Almost surely, 2999981055 is an apocalyptic number.
999981055 is a deficient number, since it is larger than the sum of its proper divisors (304926785).
999981055 is a wasteful number, since it uses less digits than its factorization.
999981055 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 318018.
The product of its (nonzero) digits is 1312200, while the sum is 55.
The square root of 999981055 is about 31622.4770535137.
The cubic root of 999981055 is about 999.9936849601.
The spelling of 999981055 in words is "nine hundred ninety-nine million, nine hundred eighty-one thousand, fifty-five".