21220000051 has 2 divisors, whose sum is σ = 21220000052. Its totient is φ = 21220000050.

The previous prime is 21220000037. The next prime is 21220000079. The reversal of 21220000051 is 15000002212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21220000051 - 2⁵ = 21220000019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21219999986 and 21220000040.

It is not a weakly prime, because it can be changed into another prime (21220000001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610000025 + 10610000026.

It is an arithmetic number, because the mean of its divisors is an integer number (10610000026).

Almost surely, 2^21220000051 is an apocalyptic number.

21220000051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220000051 is an equidigital number, since it uses as much as digits as its factorization.

21220000051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40, while the sum is 13.

Adding to 21220000051 its reverse (15000002212), we get a palindrome (36220002263).

The spelling of 21220000051 in words is "twenty-one billion, two hundred twenty million, fifty-one", and thus it is an aban number.