201121021091 has 8 divisors (see below), whose sum is σ = 204977234880. Its totient is φ = 197267084352.

The previous prime is 201121021061. The next prime is 201121021111. The reversal of 201121021091 is 190120121102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201121021091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201121021061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 390386 + ... + 744743.

It is an arithmetic number, because the mean of its divisors is an integer number (25622154360).

Almost surely, 2^201121021091 is an apocalyptic number.

201121021091 is a deficient number, since it is larger than the sum of its proper divisors (3856213789).

201121021091 is a wasteful number, since it uses less digits than its factorization.

201121021091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1138525.

The product of its (nonzero) digits is 72, while the sum is 20.

Adding to 201121021091 its reverse (190120121102), we get a palindrome (391241142193).

The spelling of 201121021091 in words is "two hundred one billion, one hundred twenty-one million, twenty-one thousand, ninety-one".