1225409621 has 2 divisors, whose sum is σ = 1225409622. Its totient is φ = 1225409620.

The previous prime is 1225409597. The next prime is 1225409671. The reversal of 1225409621 is 1269045221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1067002225 + 158407396 = 32665^2 + 12586^2 .

It is a cyclic number.

It is not a de Polignac number, because 1225409621 - 2⁶ = 1225409557 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1225409671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 612704810 + 612704811.

It is an arithmetic number, because the mean of its divisors is an integer number (612704811).

Almost surely, 2^1225409621 is an apocalyptic number.

It is an amenable number.

1225409621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225409621 is an equidigital number, since it uses as much as digits as its factorization.

1225409621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 1225409621 is about 35005.8512394714. The cubic root of 1225409621 is about 1070.1067296803.

The spelling of 1225409621 in words is "one billion, two hundred twenty-five million, four hundred nine thousand, six hundred twenty-one".