205837894209 has 32 divisors (see below), whose sum is σ = 289523808000. Its totient is φ = 129879975680.

The previous prime is 205837894121. The next prime is 205837894211. The reversal of 205837894209 is 902498738502.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 205837894209 - 2¹⁵ = 205837861441 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205837894279) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5426692 + ... + 5464490.

It is an arithmetic number, because the mean of its divisors is an integer number (9047619000).

Almost surely, 2^205837894209 is an apocalyptic number.

205837894209 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

205837894209 is a deficient number, since it is larger than the sum of its proper divisors (83685913791).

205837894209 is a wasteful number, since it uses less digits than its factorization.

205837894209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39065.

The product of its (nonzero) digits is 8709120, while the sum is 57.

The spelling of 205837894209 in words is "two hundred five billion, eight hundred thirty-seven million, eight hundred ninety-four thousand, two hundred nine".