1221122120987 has 2 divisors, whose sum is σ = 1221122120988. Its totient is φ = 1221122120986.

The previous prime is 1221122120971. The next prime is 1221122121029. The reversal of 1221122120987 is 7890212211221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221122120987 - 2⁴ = 1221122120971 is a prime.

It is a super-2 number, since 2×1221122120987² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221122120987.

It is not a weakly prime, because it can be changed into another prime (1221122120917) 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, 610561060493 + 610561060494.

It is an arithmetic number, because the mean of its divisors is an integer number (610561060494).

Almost surely, 2^{1221122120987} is an apocalyptic number.

1221122120987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221122120987 is an equidigital number, since it uses as much as digits as its factorization.

1221122120987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 38.

The spelling of 1221122120987 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, one hundred twenty thousand, nine hundred eighty-seven".