201121200091 has 16 divisors (see below), whose sum is σ = 230791121856. Its totient is φ = 171686117376.

The previous prime is 201121200079. The next prime is 201121200097. The reversal of 201121200091 is 190002121102.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 201121200091 - 2¹⁹ = 201120675803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201121200097) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16899255 + ... + 16911151.

It is an arithmetic number, because the mean of its divisors is an integer number (14424445116).

Almost surely, 2^201121200091 is an apocalyptic number.

201121200091 is a deficient number, since it is larger than the sum of its proper divisors (29669921765).

201121200091 is a wasteful number, since it uses less digits than its factorization.

201121200091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21558.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 201121200091 its reverse (190002121102), we get a palindrome (391123321193).

The spelling of 201121200091 in words is "two hundred one billion, one hundred twenty-one million, two hundred thousand, ninety-one".