1221403129 has 2 divisors, whose sum is σ = 1221403130. Its totient is φ = 1221403128.

The previous prime is 1221403111. The next prime is 1221403133. The reversal of 1221403129 is 9213041221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 768564729 + 452838400 = 27723^2 + 21280^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221403129 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221403229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610701564 + 610701565.

It is an arithmetic number, because the mean of its divisors is an integer number (610701565).

Almost surely, 2^1221403129 is an apocalyptic number.

It is an amenable number.

1221403129 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221403129 is an equidigital number, since it uses as much as digits as its factorization.

1221403129 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1221403129 is about 34948.5783544910. The cubic root of 1221403129 is about 1068.9392139303.

The spelling of 1221403129 in words is "one billion, two hundred twenty-one million, four hundred three thousand, one hundred twenty-nine".