21055000051 has 2 divisors, whose sum is σ = 21055000052. Its totient is φ = 21055000050.

The previous prime is 21055000039. The next prime is 21055000061. The reversal of 21055000051 is 15000055012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21055000051 - 2¹⁹ = 21054475763 is a prime.

It is a super-2 number, since 2×21055000051² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21054999992 and 21055000028.

It is not a weakly prime, because it can be changed into another prime (21055000061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10527500025 + 10527500026.

It is an arithmetic number, because the mean of its divisors is an integer number (10527500026).

Almost surely, 2^21055000051 is an apocalyptic number.

21055000051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21055000051 is an equidigital number, since it uses as much as digits as its factorization.

21055000051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 250, while the sum is 19.

Adding to 21055000051 its reverse (15000055012), we get a palindrome (36055055063).

The spelling of 21055000051 in words is "twenty-one billion, fifty-five million, fifty-one", and thus it is an aban number and an uban number.