1221000203 has 2 divisors, whose sum is σ = 1221000204. Its totient is φ = 1221000202.

The previous prime is 1221000181. The next prime is 1221000227. The reversal of 1221000203 is 3020001221.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221000203 - 2⁶ = 1221000139 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221000283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610500101 + 610500102.

It is an arithmetic number, because the mean of its divisors is an integer number (610500102).

Almost surely, 2^1221000203 is an apocalyptic number.

1221000203 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221000203 is an equidigital number, since it uses as much as digits as its factorization.

1221000203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 1221000203 is about 34942.8133240585. The cubic root of 1221000203 is about 1068.8216576647.

Adding to 1221000203 its reverse (3020001221), we get a palindrome (4241001424).

The spelling of 1221000203 in words is "one billion, two hundred twenty-one million, two hundred three", and thus it is an aban number.