21891575255027 has 2 divisors, whose sum is σ = 21891575255028. Its totient is φ = 21891575255026.

The previous prime is 21891575255021. The next prime is 21891575255089. The reversal of 21891575255027 is 72055257519812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21891575255027 - 2¹⁸ = 21891574992883 is a prime.

It is not a weakly prime, because it can be changed into another prime (21891575255021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10945787627513 + 10945787627514.

It is an arithmetic number, because the mean of its divisors is an integer number (10945787627514).

Almost surely, 2^{21891575255027} is an apocalyptic number.

21891575255027 is a deficient number, since it is larger than the sum of its proper divisors (1).

21891575255027 is an equidigital number, since it uses as much as digits as its factorization.

21891575255027 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17640000, while the sum is 59.

The spelling of 21891575255027 in words is "twenty-one trillion, eight hundred ninety-one billion, five hundred seventy-five million, two hundred fifty-five thousand, twenty-seven".