1221504073 has 2 divisors, whose sum is σ = 1221504074. Its totient is φ = 1221504072.

The previous prime is 1221504047. The next prime is 1221504133. The reversal of 1221504073 is 3704051221.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 710382409 + 511121664 = 26653^2 + 22608^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221504073 - 2²¹ = 1219406921 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221504023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610752036 + 610752037.

It is an arithmetic number, because the mean of its divisors is an integer number (610752037).

Almost surely, 2^1221504073 is an apocalyptic number.

It is an amenable number.

1221504073 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221504073 is an equidigital number, since it uses as much as digits as its factorization.

1221504073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 1221504073 is about 34950.0225035693. The cubic root of 1221504073 is about 1068.9686609449.

Adding to 1221504073 its reverse (3704051221), we get a palindrome (4925555294).

The spelling of 1221504073 in words is "one billion, two hundred twenty-one million, five hundred four thousand, seventy-three".