1211203020421 has 2 divisors, whose sum is σ = 1211203020422. Its totient is φ = 1211203020420.

The previous prime is 1211203020409. The next prime is 1211203020431. The reversal of 1211203020421 is 1240203021121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1159121390625 + 52081629796 = 1076625^2 + 228214^2 .

It is an emirp because it is prime and its reverse (1240203021121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1211203020421 - 2⁹ = 1211203019909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211203020431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605601510210 + 605601510211.

It is an arithmetic number, because the mean of its divisors is an integer number (605601510211).

Almost surely, 2^{1211203020421} is an apocalyptic number.

It is an amenable number.

1211203020421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211203020421 is an equidigital number, since it uses as much as digits as its factorization.

1211203020421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 1211203020421 its reverse (1240203021121), we get a palindrome (2451406041542).

The spelling of 1211203020421 in words is "one trillion, two hundred eleven billion, two hundred three million, twenty thousand, four hundred twenty-one".