999997399 has 4 divisors (see below), whose sum is σ = 1000078960. Its totient is φ = 999915840.

The previous prime is 999997357. The next prime is 999997403. The reversal of 999997399 is 993799999.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 999997399 - 2²⁹ = 463126487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999997309) 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, 18234 + ... + 48295.

It is an arithmetic number, because the mean of its divisors is an integer number (250019740).

Almost surely, 2^999997399 is an apocalyptic number.

999997399 is a deficient number, since it is larger than the sum of its proper divisors (81561).

999997399 is a wasteful number, since it uses less digits than its factorization.

999997399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81560.

The product of its digits is 100442349, while the sum is 73.

The square root of 999997399 is about 31622.7354762361. The cubic root of 999997399 is about 999.9991329992. Note that the first 3 decimals are identical.

The spelling of 999997399 in words is "nine hundred ninety-nine million, nine hundred ninety-seven thousand, three hundred ninety-nine".