225811681 has 2 divisors, whose sum is σ = 225811682. Its totient is φ = 225811680.

The previous prime is 225811639. The next prime is 225811693. The reversal of 225811681 is 186118522.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 224730081 + 1081600 = 14991^2 + 1040^2 .

It is a cyclic number.

It is not a de Polignac number, because 225811681 - 2¹⁵ = 225778913 is a prime.

It is a super-2 number, since 2×225811681² = 101981830552091522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (225812681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112905840 + 112905841.

It is an arithmetic number, because the mean of its divisors is an integer number (112905841).

Almost surely, 2^225811681 is an apocalyptic number.

It is an amenable number.

225811681 is a deficient number, since it is larger than the sum of its proper divisors (1).

225811681 is an equidigital number, since it uses as much as digits as its factorization.

225811681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7680, while the sum is 34.

The square root of 225811681 is about 15027.0316762826. The cubic root of 225811681 is about 608.9507007726.

The spelling of 225811681 in words is "two hundred twenty-five million, eight hundred eleven thousand, six hundred eighty-one".