823015409 has 2 divisors, whose sum is σ = 823015410. Its totient is φ = 823015408.

The previous prime is 823015397. The next prime is 823015411. The reversal of 823015409 is 904510328.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 810256225 + 12759184 = 28465^2 + 3572^2 .

It is a cyclic number.

It is not a de Polignac number, because 823015409 - 2⁴ = 823015393 is a prime.

Together with 823015411, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (823005409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411507704 + 411507705.

It is an arithmetic number, because the mean of its divisors is an integer number (411507705).

Almost surely, 2^823015409 is an apocalyptic number.

It is an amenable number.

823015409 is a deficient number, since it is larger than the sum of its proper divisors (1).

823015409 is an equidigital number, since it uses as much as digits as its factorization.

823015409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 823015409 is about 28688.2451362923. The cubic root of 823015409 is about 937.1360731223.

The spelling of 823015409 in words is "eight hundred twenty-three million, fifteen thousand, four hundred nine".