21221110193 has 2 divisors, whose sum is σ = 21221110194. Its totient is φ = 21221110192.

The previous prime is 21221110187. The next prime is 21221110223. The reversal of 21221110193 is 39101112212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19631652769 + 1589457424 = 140113^2 + 39868^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221110193 - 2¹² = 21221106097 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221130193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610555096 + 10610555097.

It is an arithmetic number, because the mean of its divisors is an integer number (10610555097).

Almost surely, 2^21221110193 is an apocalyptic number.

It is an amenable number.

21221110193 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221110193 is an equidigital number, since it uses as much as digits as its factorization.

21221110193 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 23.

The spelling of 21221110193 in words is "twenty-one billion, two hundred twenty-one million, one hundred ten thousand, one hundred ninety-three".