201001091 has 4 divisors (see below), whose sum is σ = 201154800. Its totient is φ = 200847384.

The previous prime is 201001067. The next prime is 201001109. The reversal of 201001091 is 190100102.

201001091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190100102 = 2 ⋅95050051.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201001091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201001891) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74876 + ... + 77513.

It is an arithmetic number, because the mean of its divisors is an integer number (50288700).

Almost surely, 2^201001091 is an apocalyptic number.

201001091 is a deficient number, since it is larger than the sum of its proper divisors (153709).

201001091 is a wasteful number, since it uses less digits than its factorization.

201001091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153708.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 201001091 is about 14177.4853553090. The cubic root of 201001091 is about 585.7776601011. Note that the first 3 decimals are identical.

Adding to 201001091 its reverse (190100102), we get a palindrome (391101193).

The spelling of 201001091 in words is "two hundred one million, one thousand, ninety-one".