999226861 has 4 divisors (see below), whose sum is σ = 1018080252. Its totient is φ = 980373472.

The previous prime is 999226849. The next prime is 999226889. The reversal of 999226861 is 168622999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 168622999 = 1559 ⋅108161.

It can be written as a sum of positive squares in 2 ways, for example, as 893651236 + 105575625 = 29894^2 + 10275^2 .

It is a cyclic number.

It is not a de Polignac number, because 999226861 - 2⁵ = 999226829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 999226799 and 999226808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999226801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9426616 + ... + 9426721.

It is an arithmetic number, because the mean of its divisors is an integer number (254520063).

Almost surely, 2^999226861 is an apocalyptic number.

It is an amenable number.

999226861 is a deficient number, since it is larger than the sum of its proper divisors (18853391).

999226861 is a wasteful number, since it uses less digits than its factorization.

999226861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18853390.

The product of its digits is 839808, while the sum is 52.

The square root of 999226861 is about 31610.5498370402. The cubic root of 999226861 is about 999.7422205555.

The spelling of 999226861 in words is "nine hundred ninety-nine million, two hundred twenty-six thousand, eight hundred sixty-one".