201212120091 has 4 divisors (see below), whose sum is σ = 268282826792. Its totient is φ = 134141413392.

The previous prime is 201212120089. The next prime is 201212120093. The reversal of 201212120091 is 190021212102.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (201212120089) and next prime (201212120093).

It is not a de Polignac number, because 201212120091 - 2¹ = 201212120089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201212120093) 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, 33535353346 + ... + 33535353351.

It is an arithmetic number, because the mean of its divisors is an integer number (67070706698).

Almost surely, 2^201212120091 is an apocalyptic number.

201212120091 is a deficient number, since it is larger than the sum of its proper divisors (67070706701).

201212120091 is an equidigital number, since it uses as much as digits as its factorization.

201212120091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67070706700.

The product of its (nonzero) digits is 144, while the sum is 21.

Adding to 201212120091 its reverse (190021212102), we get a palindrome (391233332193).

The spelling of 201212120091 in words is "two hundred one billion, two hundred twelve million, one hundred twenty thousand, ninety-one".