21556263162899 has 2 divisors, whose sum is σ = 21556263162900. Its totient is φ = 21556263162898.

The previous prime is 21556263162883. The next prime is 21556263162943. The reversal of 21556263162899 is 99826136265512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21556263162899 - 2⁴ = 21556263162883 is a prime.

It is not a weakly prime, because it can be changed into another prime (21556263162199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10778131581449 + 10778131581450.

It is an arithmetic number, because the mean of its divisors is an integer number (10778131581450).

Almost surely, 2^{21556263162899} is an apocalyptic number.

21556263162899 is a deficient number, since it is larger than the sum of its proper divisors (1).

21556263162899 is an equidigital number, since it uses as much as digits as its factorization.

21556263162899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 83980800, while the sum is 65.

The spelling of 21556263162899 in words is "twenty-one trillion, five hundred fifty-six billion, two hundred sixty-three million, one hundred sixty-two thousand, eight hundred ninety-nine".