1221220020511 has 2 divisors, whose sum is σ = 1221220020512. Its totient is φ = 1221220020510.

The previous prime is 1221220020473. The next prime is 1221220020529. The reversal of 1221220020511 is 1150200221221.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221220020511 - 2¹¹ = 1221220018463 is a prime.

It is a super-2 number, since 2×1221220020511² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221220023511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610610010255 + 610610010256.

It is an arithmetic number, because the mean of its divisors is an integer number (610610010256).

Almost surely, 2^{1221220020511} is an apocalyptic number.

1221220020511 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221220020511 is an equidigital number, since it uses as much as digits as its factorization.

1221220020511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 160, while the sum is 19.

Adding to 1221220020511 its reverse (1150200221221), we get a palindrome (2371420241732).

The spelling of 1221220020511 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, twenty thousand, five hundred eleven".