1221220019969 has 2 divisors, whose sum is σ = 1221220019970. Its totient is φ = 1221220019968.

The previous prime is 1221220019953. The next prime is 1221220020029. The reversal of 1221220019969 is 9699100221221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1051059644944 + 170160375025 = 1025212^2 + 412505^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221220019969 - 2⁴ = 1221220019953 is a prime.

It is a super-2 number, since 2×1221220019969² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221220019939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610610009984 + 610610009985.

It is an arithmetic number, because the mean of its divisors is an integer number (610610009985).

Almost surely, 2^{1221220019969} is an apocalyptic number.

It is an amenable number.

1221220019969 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221220019969 is an equidigital number, since it uses as much as digits as its factorization.

1221220019969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 44.

The spelling of 1221220019969 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, nineteen thousand, nine hundred sixty-nine".