211865802481 has 2 divisors, whose sum is σ = 211865802482. Its totient is φ = 211865802480.

The previous prime is 211865802469. The next prime is 211865802521. The reversal of 211865802481 is 184208568112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 187654442481 + 24211360000 = 433191^2 + 155600^2 .

It is a cyclic number.

It is not a de Polignac number, because 211865802481 - 2⁷ = 211865802353 is a prime.

It is a super-2 number, since 2×211865802481² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (211865802451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105932901240 + 105932901241.

It is an arithmetic number, because the mean of its divisors is an integer number (105932901241).

Almost surely, 2^211865802481 is an apocalyptic number.

It is an amenable number.

211865802481 is a deficient number, since it is larger than the sum of its proper divisors (1).

211865802481 is an equidigital number, since it uses as much as digits as its factorization.

211865802481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 245760, while the sum is 46.

The spelling of 211865802481 in words is "two hundred eleven billion, eight hundred sixty-five million, eight hundred two thousand, four hundred eighty-one".