1221231111409 has 8 divisors (see below), whose sum is σ = 1234977355080. Its totient is φ = 1207485413376.

The previous prime is 1221231111323. The next prime is 1221231111433. The reversal of 1221231111409 is 9041111321221.

It can be written as a sum of positive squares in 4 ways, for example, as 26407225009 + 1194823886400 = 162503^2 + 1093080^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221231111409 - 2¹¹ = 1221231109361 is a prime.

It is a super-2 number, since 2×1221231111409² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221231111449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5820129 + ... + 6026305.

It is an arithmetic number, because the mean of its divisors is an integer number (154372169385).

Almost surely, 2^{1221231111409} is an apocalyptic number.

It is an amenable number.

1221231111409 is a deficient number, since it is larger than the sum of its proper divisors (13746243671).

1221231111409 is an equidigital number, since it uses as much as digits as its factorization.

1221231111409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272819.

The product of its (nonzero) digits is 864, while the sum is 28.

The spelling of 1221231111409 in words is "one trillion, two hundred twenty-one billion, two hundred thirty-one million, one hundred eleven thousand, four hundred nine".