1221122209997 has 2 divisors, whose sum is σ = 1221122209998. Its totient is φ = 1221122209996.

The previous prime is 1221122209991. The next prime is 1221122210059. The reversal of 1221122209997 is 7999022211221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1217566592356 + 3555617641 = 1103434^2 + 59629^2 .

It is an emirp because it is prime and its reverse (7999022211221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221122209997 - 2¹⁰ = 1221122208973 is a prime.

It is a super-2 number, since 2×1221122209997² (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 (1221122209991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610561104998 + 610561104999.

It is an arithmetic number, because the mean of its divisors is an integer number (610561104999).

Almost surely, 2^{1221122209997} is an apocalyptic number.

It is an amenable number.

1221122209997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221122209997 is an equidigital number, since it uses as much as digits as its factorization.

1221122209997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 47.

The spelling of 1221122209997 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, two hundred nine thousand, nine hundred ninety-seven".