1211220203951 has 2 divisors, whose sum is σ = 1211220203952. Its totient is φ = 1211220203950.

The previous prime is 1211220203927. The next prime is 1211220203957. The reversal of 1211220203951 is 1593020221121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1211220203951 - 2³⁰ = 1210146462127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211220203957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605610101975 + 605610101976.

It is an arithmetic number, because the mean of its divisors is an integer number (605610101976).

Almost surely, 2^{1211220203951} is an apocalyptic number.

1211220203951 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211220203951 is an equidigital number, since it uses as much as digits as its factorization.

1211220203951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 29.

The spelling of 1211220203951 in words is "one trillion, two hundred eleven billion, two hundred twenty million, two hundred three thousand, nine hundred fifty-one".