1221001020203 has 2 divisors, whose sum is σ = 1221001020204. Its totient is φ = 1221001020202.

The previous prime is 1221001020199. The next prime is 1221001020221. The reversal of 1221001020203 is 3020201001221.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221001020203 - 2² = 1221001020199 is a prime.

It is a super-2 number, since 2×1221001020203² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221001020233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610500510101 + 610500510102.

It is an arithmetic number, because the mean of its divisors is an integer number (610500510102).

Almost surely, 2^{1221001020203} is an apocalyptic number.

1221001020203 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221001020203 is an equidigital number, since it uses as much as digits as its factorization.

1221001020203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 1221001020203 its reverse (3020201001221), we get a palindrome (4241202021424).

The spelling of 1221001020203 in words is "one trillion, two hundred twenty-one billion, one million, twenty thousand, two hundred three".