209396823523 has 2 divisors, whose sum is σ = 209396823524. Its totient is φ = 209396823522.

The previous prime is 209396823497. The next prime is 209396823529. The reversal of 209396823523 is 325328693902.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 209396823523 - 2⁹ = 209396823011 is a prime.

It is a super-3 number, since 3×209396823523³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (209396823529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104698411761 + 104698411762.

It is an arithmetic number, because the mean of its divisors is an integer number (104698411762).

Almost surely, 2^209396823523 is an apocalyptic number.

209396823523 is a deficient number, since it is larger than the sum of its proper divisors (1).

209396823523 is an equidigital number, since it uses as much as digits as its factorization.

209396823523 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4199040, while the sum is 52.

The spelling of 209396823523 in words is "two hundred nine billion, three hundred ninety-six million, eight hundred twenty-three thousand, five hundred twenty-three".