21212241091 has 2 divisors, whose sum is σ = 21212241092. Its totient is φ = 21212241090.

The previous prime is 21212241049. The next prime is 21212241143. The reversal of 21212241091 is 19014221212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21212241091 - 2⁷ = 21212240963 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212242091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606120545 + 10606120546.

It is an arithmetic number, because the mean of its divisors is an integer number (10606120546).

Almost surely, 2^21212241091 is an apocalyptic number.

21212241091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212241091 is an equidigital number, since it uses as much as digits as its factorization.

21212241091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 25.

The spelling of 21212241091 in words is "twenty-one billion, two hundred twelve million, two hundred forty-one thousand, ninety-one".