1221601 has 2 divisors, whose sum is σ = 1221602. Its totient is φ = 1221600.

The previous prime is 1221593. The next prime is 1221631. The reversal of 1221601 is 1061221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1221025 + 576 = 1105^2 + 24^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221601 - 2³ = 1221593 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610800 + 610801.

It is an arithmetic number, because the mean of its divisors is an integer number (610801).

2^1221601 is an apocalyptic number.

It is an amenable number.

1221601 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221601 is an equidigital number, since it uses as much as digits as its factorization.

1221601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1221601 is about 1105.2606027539. The cubic root of 1221601 is about 106.8996934608.

Adding to 1221601 its reverse (1061221), we get a palindrome (2282822).

The spelling of 1221601 in words is "one million, two hundred twenty-one thousand, six hundred one".