21155056063 has 2 divisors, whose sum is σ = 21155056064. Its totient is φ = 21155056062.

The previous prime is 21155056049. The next prime is 21155056067. The reversal of 21155056063 is 36065055112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21155056063 - 2⁵ = 21155056031 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21155056067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10577528031 + 10577528032.

It is an arithmetic number, because the mean of its divisors is an integer number (10577528032).

Almost surely, 2^21155056063 is an apocalyptic number.

21155056063 is a deficient number, since it is larger than the sum of its proper divisors (1).

21155056063 is an equidigital number, since it uses as much as digits as its factorization.

21155056063 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27000, while the sum is 34.

The spelling of 21155056063 in words is "twenty-one billion, one hundred fifty-five million, fifty-six thousand, sixty-three".