111211211122621 has 2 divisors, whose sum is σ = 111211211122622. Its totient is φ = 111211211122620.

The previous prime is 111211211122573. The next prime is 111211211122631. The reversal of 111211211122621 is 126221112112111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88648815622500 + 22562395500121 = 9415350^2 + 4749989^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111211211122621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111211211122631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55605605561310 + 55605605561311.

It is an arithmetic number, because the mean of its divisors is an integer number (55605605561311).

Almost surely, 2^{111211211122621} is an apocalyptic number.

It is an amenable number.

111211211122621 is a deficient number, since it is larger than the sum of its proper divisors (1).

111211211122621 is an equidigital number, since it uses as much as digits as its factorization.

111211211122621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 25.

Adding to 111211211122621 its reverse (126221112112111), we get a palindrome (237432323234732).

The spelling of 111211211122621 in words is "one hundred eleven trillion, two hundred eleven billion, two hundred eleven million, one hundred twenty-two thousand, six hundred twenty-one".