21211155107 has 2 divisors, whose sum is σ = 21211155108. Its totient is φ = 21211155106.

The previous prime is 21211155103. The next prime is 21211155113. The reversal of 21211155107 is 70155111212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21211155107 - 2² = 21211155103 is a prime.

It is not a weakly prime, because it can be changed into another prime (21211155103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605577553 + 10605577554.

It is an arithmetic number, because the mean of its divisors is an integer number (10605577554).

Almost surely, 2^21211155107 is an apocalyptic number.

21211155107 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211155107 is an equidigital number, since it uses as much as digits as its factorization.

21211155107 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 700, while the sum is 26.

Adding to 21211155107 its reverse (70155111212), we get a palindrome (91366266319).

The spelling of 21211155107 in words is "twenty-one billion, two hundred eleven million, one hundred fifty-five thousand, one hundred seven".