201023009 has 4 divisors (see below), whose sum is σ = 219297840. Its totient is φ = 182748180.

The previous prime is 201022993. The next prime is 201023029. The reversal of 201023009 is 900320102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 201023009 - 2⁴ = 201022993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201023029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9137399 + ... + 9137420.

It is an arithmetic number, because the mean of its divisors is an integer number (54824460).

Almost surely, 2^201023009 is an apocalyptic number.

It is an amenable number.

201023009 is a deficient number, since it is larger than the sum of its proper divisors (18274831).

201023009 is a wasteful number, since it uses less digits than its factorization.

201023009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18274830.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 201023009 is about 14178.2583204003. The cubic root of 201023009 is about 585.7989512096.

The spelling of 201023009 in words is "two hundred one million, twenty-three thousand, nine".