1225621 has 2 divisors, whose sum is σ = 1225622. Its totient is φ = 1225620.

The previous prime is 1225603. The next prime is 1225643. The reversal of 1225621 is 1265221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1179396 + 46225 = 1086^2 + 215^2 .

It is a cyclic number.

It is not a de Polignac number, because 1225621 - 2⁵ = 1225589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1225691) 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, 612810 + 612811.

It is an arithmetic number, because the mean of its divisors is an integer number (612811).

2^1225621 is an apocalyptic number.

It is an amenable number.

1225621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225621 is an equidigital number, since it uses as much as digits as its factorization.

1225621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 240, while the sum is 19.

The square root of 1225621 is about 1107.0776847177. The cubic root of 1225621 is about 107.0168256069.

The spelling of 1225621 in words is "one million, two hundred twenty-five thousand, six hundred twenty-one".