1221004913 has 2 divisors, whose sum is σ = 1221004914. Its totient is φ = 1221004912.

The previous prime is 1221004903. The next prime is 1221005041. The reversal of 1221004913 is 3194001221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1155184144 + 65820769 = 33988^2 + 8113^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221004913 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221004903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610502456 + 610502457.

It is an arithmetic number, because the mean of its divisors is an integer number (610502457).

Almost surely, 2^1221004913 is an apocalyptic number.

It is an amenable number.

1221004913 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221004913 is an equidigital number, since it uses as much as digits as its factorization.

1221004913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1221004913 is about 34942.8807198262. The cubic root of 1221004913 is about 1068.8230319871.

The spelling of 1221004913 in words is "one billion, two hundred twenty-one million, four thousand, nine hundred thirteen".