999973409 has 2 divisors, whose sum is σ = 999973410. Its totient is φ = 999973408.

The previous prime is 999973399. The next prime is 999973421. The reversal of 999973409 is 904379999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 579846400 + 420127009 = 24080^2 + 20497^2 .

It is a cyclic number.

It is not a de Polignac number, because 999973409 - 2⁸ = 999973153 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (999973309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499986704 + 499986705.

It is an arithmetic number, because the mean of its divisors is an integer number (499986705).

Almost surely, 2^999973409 is an apocalyptic number.

It is an amenable number.

999973409 is a deficient number, since it is larger than the sum of its proper divisors (1).

999973409 is an equidigital number, since it uses as much as digits as its factorization.

999973409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4960116, while the sum is 59.

The square root of 999973409 is about 31622.3561582625. The cubic root of 999973409 is about 999.9911362548.

The spelling of 999973409 in words is "nine hundred ninety-nine million, nine hundred seventy-three thousand, four hundred nine".