1211201020021 has 2 divisors, whose sum is σ = 1211201020022. Its totient is φ = 1211201020020.

The previous prime is 1211201019997. The next prime is 1211201020049. The reversal of 1211201020021 is 1200201021121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 888475908100 + 322725111921 = 942590^2 + 568089^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211201020021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211201019983 and 1211201020010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211201024021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605600510010 + 605600510011.

It is an arithmetic number, because the mean of its divisors is an integer number (605600510011).

Almost surely, 2^{1211201020021} is an apocalyptic number.

It is an amenable number.

1211201020021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211201020021 is an equidigital number, since it uses as much as digits as its factorization.

1211201020021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1211201020021 its reverse (1200201021121), we get a palindrome (2411402041142).

The spelling of 1211201020021 in words is "one trillion, two hundred eleven billion, two hundred one million, twenty thousand, twenty-one".