999693257 has 4 divisors (see below), whose sum is σ = 1003984020. Its totient is φ = 995402496.

The previous prime is 999693241. The next prime is 999693271. The reversal of 999693257 is 752396999.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 194212096 + 805481161 = 13936^2 + 28381^2 .

It is a cyclic number.

It is not a de Polignac number, because 999693257 - 2⁴ = 999693241 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 999693196 and 999693205.

It is not an unprimeable number, because it can be changed into a prime (999693217) 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 3 ways as a sum of consecutive naturals, for example, 2145032 + ... + 2145497.

It is an arithmetic number, because the mean of its divisors is an integer number (250996005).

Almost surely, 2^999693257 is an apocalyptic number.

It is an amenable number.

999693257 is a deficient number, since it is larger than the sum of its proper divisors (4290763).

999693257 is a wasteful number, since it uses less digits than its factorization.

999693257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4290762.

The product of its digits is 8266860, while the sum is 59.

The square root of 999693257 is about 31617.9261970168. The cubic root of 999693257 is about 999.8977418770.

The spelling of 999693257 in words is "nine hundred ninety-nine million, six hundred ninety-three thousand, two hundred fifty-seven".