21111112207 has 2 divisors, whose sum is σ = 21111112208. Its totient is φ = 21111112206.

The previous prime is 21111112177. The next prime is 21111112229. The reversal of 21111112207 is 70221111112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21111112207 - 2²³ = 21102723599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111112277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555556103 + 10555556104.

It is an arithmetic number, because the mean of its divisors is an integer number (10555556104).

Almost surely, 2^21111112207 is an apocalyptic number.

21111112207 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111112207 is an equidigital number, since it uses as much as digits as its factorization.

21111112207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 19.

Adding to 21111112207 its reverse (70221111112), we get a palindrome (91332223319).

The spelling of 21111112207 in words is "twenty-one billion, one hundred eleven million, one hundred twelve thousand, two hundred seven".