221867185481 has 2 divisors, whose sum is σ = 221867185482. Its totient is φ = 221867185480.

The previous prime is 221867185469. The next prime is 221867185517. The reversal of 221867185481 is 184581768122.

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., 171698353225 + 50168832256 = 414365^2 + 223984^2 .

It is a cyclic number.

It is not a de Polignac number, because 221867185481 - 2²² = 221862991177 is a prime.

It is a super-2 number, since 2×221867185481² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221867145481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110933592740 + 110933592741.

It is an arithmetic number, because the mean of its divisors is an integer number (110933592741).

Almost surely, 2^221867185481 is an apocalyptic number.

It is an amenable number.

221867185481 is a deficient number, since it is larger than the sum of its proper divisors (1).

221867185481 is an equidigital number, since it uses as much as digits as its factorization.

221867185481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1720320, while the sum is 53.

The spelling of 221867185481 in words is "two hundred twenty-one billion, eight hundred sixty-seven million, one hundred eighty-five thousand, four hundred eighty-one".