221152681 has 2 divisors, whose sum is σ = 221152682. Its totient is φ = 221152680.

The previous prime is 221152627. The next prime is 221152691. The reversal of 221152681 is 186251122.

221152681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111091600 + 110061081 = 10540^2 + 10491^2 .

It is a cyclic number.

It is not a de Polignac number, because 221152681 - 2⁷ = 221152553 is a prime.

It is a super-2 number, since 2×221152681² = 97817016626975522, which contains 22 as substring.

It is a Chen prime.

It is equal to p_12182464 and since 221152681 and 12182464 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (221152621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110576340 + 110576341.

It is an arithmetic number, because the mean of its divisors is an integer number (110576341).

Almost surely, 2^221152681 is an apocalyptic number.

It is an amenable number.

221152681 is a deficient number, since it is larger than the sum of its proper divisors (1).

221152681 is an equidigital number, since it uses as much as digits as its factorization.

221152681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1920, while the sum is 28.

The square root of 221152681 is about 14871.2030784332. The cubic root of 221152681 is about 604.7335584273.

The spelling of 221152681 in words is "two hundred twenty-one million, one hundred fifty-two thousand, six hundred eighty-one".