1220443412521 has 2 divisors, whose sum is σ = 1220443412522. Its totient is φ = 1220443412520.

The previous prime is 1220443412519. The next prime is 1220443412533. The reversal of 1220443412521 is 1252143440221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1219392356121 + 1051056400 = 1104261^2 + 32420^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220443412521 - 2¹ = 1220443412519 is a prime.

Together with 1220443412519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1220443412921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610221706260 + 610221706261.

It is an arithmetic number, because the mean of its divisors is an integer number (610221706261).

Almost surely, 2^{1220443412521} is an apocalyptic number.

It is an amenable number.

1220443412521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220443412521 is an equidigital number, since it uses as much as digits as its factorization.

1220443412521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15360, while the sum is 31.

Adding to 1220443412521 its reverse (1252143440221), we get a palindrome (2472586852742).

The spelling of 1220443412521 in words is "one trillion, two hundred twenty billion, four hundred forty-three million, four hundred twelve thousand, five hundred twenty-one".