1211020120221 has 4 divisors (see below), whose sum is σ = 1614693493632. Its totient is φ = 807346746812.

The previous prime is 1211020120213. The next prime is 1211020120229. The reversal of 1211020120221 is 1220210201121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1211020120213) and next prime (1211020120229).

It is a cyclic number.

It is not a de Polignac number, because 1211020120221 - 2³ = 1211020120213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211020120221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211020120229) 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, 201836686701 + ... + 201836686706.

It is an arithmetic number, because the mean of its divisors is an integer number (403673373408).

Almost surely, 2^{1211020120221} is an apocalyptic number.

It is an amenable number.

1211020120221 is a deficient number, since it is larger than the sum of its proper divisors (403673373411).

1211020120221 is an equidigital number, since it uses as much as digits as its factorization.

1211020120221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403673373410.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1211020120221 its reverse (1220210201121), we get a palindrome (2431230321342).

The spelling of 1211020120221 in words is "one trillion, two hundred eleven billion, twenty million, one hundred twenty thousand, two hundred twenty-one".