21206254364227 has 2 divisors, whose sum is σ = 21206254364228. Its totient is φ = 21206254364226.

The previous prime is 21206254364201. The next prime is 21206254364257. The reversal of 21206254364227 is 72246345260212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21206254364227 is a prime.

It is not a weakly prime, because it can be changed into another prime (21206254364257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10603127182113 + 10603127182114.

It is an arithmetic number, because the mean of its divisors is an integer number (10603127182114).

Almost surely, 2^{21206254364227} is an apocalyptic number.

21206254364227 is a deficient number, since it is larger than the sum of its proper divisors (1).

21206254364227 is an equidigital number, since it uses as much as digits as its factorization.

21206254364227 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1935360, while the sum is 46.

The spelling of 21206254364227 in words is "twenty-one trillion, two hundred six billion, two hundred fifty-four million, three hundred sixty-four thousand, two hundred twenty-seven".