21111112801 has 2 divisors, whose sum is σ = 21111112802. Its totient is φ = 21111112800.

The previous prime is 21111112793. The next prime is 21111112849. The reversal of 21111112801 is 10821111112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20464733025 + 646379776 = 143055^2 + 25424^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111112801 - 2³ = 21111112793 is a prime.

It is not a weakly prime, because it can be changed into another prime (21111115801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555556400 + 10555556401.

It is an arithmetic number, because the mean of its divisors is an integer number (10555556401).

Almost surely, 2^21111112801 is an apocalyptic number.

It is an amenable number.

21111112801 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111112801 is an equidigital number, since it uses as much as digits as its factorization.

21111112801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 19.

Adding to 21111112801 its reverse (10821111112), we get a palindrome (31932223913).

The spelling of 21111112801 in words is "twenty-one billion, one hundred eleven million, one hundred twelve thousand, eight hundred one".