201663409 has 4 divisors (see below), whose sum is σ = 203929380. Its totient is φ = 199397440.

The previous prime is 201663389. The next prime is 201663439. The reversal of 201663409 is 904366102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 40449600 + 161213809 = 6360^2 + 12697^2 .

It is a cyclic number.

It is not a de Polignac number, because 201663409 - 2⁷ = 201663281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201663439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1132852 + ... + 1133029.

It is an arithmetic number, because the mean of its divisors is an integer number (50982345).

Almost surely, 2^201663409 is an apocalyptic number.

It is an amenable number.

201663409 is a deficient number, since it is larger than the sum of its proper divisors (2265971).

201663409 is an equidigital number, since it uses as much as digits as its factorization.

201663409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2265970.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 201663409 is about 14200.8242366420. The cubic root of 201663409 is about 586.4203526866.

The spelling of 201663409 in words is "two hundred one million, six hundred sixty-three thousand, four hundred nine".