201100211212121 has 4 divisors (see below), whose sum is σ = 216569458228452. Its totient is φ = 185630964195792.

The previous prime is 201100211212051. The next prime is 201100211212139. The reversal of 201100211212121 is 121212112001102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 72387101979721 + 128713109232400 = 8508061^2 + 11345180^2 .

It is a cyclic number.

It is not a de Polignac number, because 201100211212121 - 2¹⁸ = 201100210949977 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 201100211212121.

It is not an unprimeable number, because it can be changed into a prime (201100211212141) 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, 7734623508146 + ... + 7734623508171.

It is an arithmetic number, because the mean of its divisors is an integer number (54142364557113).

Almost surely, 2^{201100211212121} is an apocalyptic number.

It is an amenable number.

201100211212121 is a deficient number, since it is larger than the sum of its proper divisors (15469247016331).

201100211212121 is a wasteful number, since it uses less digits than its factorization.

201100211212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15469247016330.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 201100211212121 its reverse (121212112001102), we get a palindrome (322312323213223).

The spelling of 201100211212121 in words is "two hundred one trillion, one hundred billion, two hundred eleven million, two hundred twelve thousand, one hundred twenty-one".