1221123111013 has 4 divisors (see below), whose sum is σ = 1315055658028. Its totient is φ = 1127190564000.

The previous prime is 1221123111001. The next prime is 1221123111031. The reversal of 1221123111013 is 3101113211221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 281002829409 + 940120281604 = 530097^2 + 969598^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221123111013 - 2¹³ = 1221123102821 is a prime.

It is a super-2 number, since 2×1221123111013² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221123111073) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46966273488 + ... + 46966273513.

It is an arithmetic number, because the mean of its divisors is an integer number (328763914507).

Almost surely, 2^{1221123111013} is an apocalyptic number.

1221123111013 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1221123111013 is a deficient number, since it is larger than the sum of its proper divisors (93932547015).

1221123111013 is an equidigital number, since it uses as much as digits as its factorization.

1221123111013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93932547014.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 1221123111013 its reverse (3101113211221), we get a palindrome (4322236322234).

The spelling of 1221123111013 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-three million, one hundred eleven thousand, thirteen".