1221021203 has 2 divisors, whose sum is σ = 1221021204. Its totient is φ = 1221021202.

The previous prime is 1221021173. The next prime is 1221021223. The reversal of 1221021203 is 3021201221.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221021203 - 2⁸ = 1221020947 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221021223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610510601 + 610510602.

It is an arithmetic number, because the mean of its divisors is an integer number (610510602).

Almost surely, 2^1221021203 is an apocalyptic number.

1221021203 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221021203 is an equidigital number, since it uses as much as digits as its factorization.

1221021203 is an evil number, because the sum of its binary digits is even.

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

The square root of 1221021203 is about 34943.1138137402. The cubic root of 1221021203 is about 1068.8277851893.

Adding to 1221021203 its reverse (3021201221), we get a palindrome (4242222424).

The spelling of 1221021203 in words is "one billion, two hundred twenty-one million, twenty-one thousand, two hundred three".