21221192101 has 2 divisors, whose sum is σ = 21221192102. Its totient is φ = 21221192100.

The previous prime is 21221192087. The next prime is 21221192117. The reversal of 21221192101 is 10129112212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18029507076 + 3191685025 = 134274^2 + 56495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221192101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221195101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610596050 + 10610596051.

It is an arithmetic number, because the mean of its divisors is an integer number (10610596051).

Almost surely, 2^21221192101 is an apocalyptic number.

It is an amenable number.

21221192101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221192101 is an equidigital number, since it uses as much as digits as its factorization.

21221192101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 22.

The spelling of 21221192101 in words is "twenty-one billion, two hundred twenty-one million, one hundred ninety-two thousand, one hundred one".