1211022001221 has 16 divisors (see below), whose sum is σ = 1654176023808. Its totient is φ = 787610304000.

The previous prime is 1211022001199. The next prime is 1211022001223. The reversal of 1211022001221 is 1221002201121.

It is not a de Polignac number, because 1211022001221 - 2⁶ = 1211022001157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211022001221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211022001223) 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, 1878285 + ... + 2439261.

It is an arithmetic number, because the mean of its divisors is an integer number (103386001488).

Almost surely, 2^{1211022001221} is an apocalyptic number.

It is an amenable number.

1211022001221 is a deficient number, since it is larger than the sum of its proper divisors (443154022587).

1211022001221 is a wasteful number, since it uses less digits than its factorization.

1211022001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578572.

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

Adding to 1211022001221 its reverse (1221002201121), we get a palindrome (2432024202342).

The spelling of 1211022001221 in words is "one trillion, two hundred eleven billion, twenty-two million, one thousand, two hundred twenty-one".