21155001107 has 2 divisors, whose sum is σ = 21155001108. Its totient is φ = 21155001106.

The previous prime is 21155001103. The next prime is 21155001151. The reversal of 21155001107 is 70110055112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21155001107 - 2² = 21155001103 is a prime.

It is not a weakly prime, because it can be changed into another prime (21155001103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10577500553 + 10577500554.

It is an arithmetic number, because the mean of its divisors is an integer number (10577500554).

Almost surely, 2^21155001107 is an apocalyptic number.

21155001107 is a deficient number, since it is larger than the sum of its proper divisors (1).

21155001107 is an equidigital number, since it uses as much as digits as its factorization.

21155001107 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 350, while the sum is 23.

Adding to 21155001107 its reverse (70110055112), we get a palindrome (91265056219).

The spelling of 21155001107 in words is "twenty-one billion, one hundred fifty-five million, one thousand, one hundred seven".