999918661 has 8 divisors (see below), whose sum is σ = 1148181824. Its totient is φ = 853009920.

The previous prime is 999918659. The next prime is 999918709. The reversal of 999918661 is 166819999.

999918661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 999918661 - 2¹ = 999918659 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 999918596 and 999918605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999918761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 337020 + ... + 339973.

It is an arithmetic number, because the mean of its divisors is an integer number (143522728).

Almost surely, 2^999918661 is an apocalyptic number.

It is an amenable number.

999918661 is a deficient number, since it is larger than the sum of its proper divisors (148263163).

999918661 is a wasteful number, since it uses less digits than its factorization.

999918661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677211.

The product of its digits is 1889568, while the sum is 58.

The square root of 999918661 is about 31621.4904930176. The cubic root of 999918661 is about 999.9728862649.

The spelling of 999918661 in words is "nine hundred ninety-nine million, nine hundred eighteen thousand, six hundred sixty-one".