1221120020137 has 2 divisors, whose sum is σ = 1221120020138. Its totient is φ = 1221120020136.

The previous prime is 1221120020077. The next prime is 1221120020149. The reversal of 1221120020137 is 7310200211221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1199942785561 + 21177234576 = 1095419^2 + 145524^2 .

It is an emirp because it is prime and its reverse (7310200211221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221120020137 - 2²³ = 1221111631529 is a prime.

It is a super-2 number, since 2×1221120020137² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221120020167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610560010068 + 610560010069.

It is an arithmetic number, because the mean of its divisors is an integer number (610560010069).

Almost surely, 2^{1221120020137} is an apocalyptic number.

It is an amenable number.

1221120020137 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221120020137 is an equidigital number, since it uses as much as digits as its factorization.

1221120020137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 336, while the sum is 22.

Adding to 1221120020137 its reverse (7310200211221), we get a palindrome (8531320231358).

The spelling of 1221120020137 in words is "one trillion, two hundred twenty-one billion, one hundred twenty million, twenty thousand, one hundred thirty-seven".