1228493921 has 2 divisors, whose sum is σ = 1228493922. Its totient is φ = 1228493920.

The previous prime is 1228493897. The next prime is 1228493927. The reversal of 1228493921 is 1293948221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1212780625 + 15713296 = 34825^2 + 3964^2 .

It is an emirp because it is prime and its reverse (1293948221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1228493921 - 2²² = 1224299617 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1228493927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 614246960 + 614246961.

It is an arithmetic number, because the mean of its divisors is an integer number (614246961).

Almost surely, 2^1228493921 is an apocalyptic number.

It is an amenable number.

1228493921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1228493921 is an equidigital number, since it uses as much as digits as its factorization.

1228493921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 41.

The square root of 1228493921 is about 35049.8776174754. The cubic root of 1228493921 is about 1071.0037807292.

The spelling of 1228493921 in words is "one billion, two hundred twenty-eight million, four hundred ninety-three thousand, nine hundred twenty-one".