203991066 has 24 divisors (see below), whose sum is σ = 442408980. Its totient is φ = 67931136.

The previous prime is 203991037. The next prime is 203991079. The reversal of 203991066 is 660199302.

It can be written as a sum of positive squares in 2 ways, for example, as 173686041 + 30305025 = 13179^2 + 5505^2 .

It is a super-2 number, since 2×203991066² = 83224710015632712, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 203991066.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15840 + ... + 25668.

Almost surely, 2^203991066 is an apocalyptic number.

203991066 is an abundant number, since it is smaller than the sum of its proper divisors (238417914).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

203991066 is a wasteful number, since it uses less digits than its factorization.

203991066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10990 (or 10987 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 203991066 is about 14282.5441011047. The cubic root of 203991066 is about 588.6679380398.

The spelling of 203991066 in words is "two hundred three million, nine hundred ninety-one thousand, sixty-six".