227561821 has 2 divisors, whose sum is σ = 227561822. Its totient is φ = 227561820.

The previous prime is 227561801. The next prime is 227561857. The reversal of 227561821 is 128165722.

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., 163481796 + 64080025 = 12786^2 + 8005^2 .

It is a cyclic number.

It is not a de Polignac number, because 227561821 - 2⁷ = 227561693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (227561801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 113780910 + 113780911.

It is an arithmetic number, because the mean of its divisors is an integer number (113780911).

Almost surely, 2^227561821 is an apocalyptic number.

It is an amenable number.

227561821 is a deficient number, since it is larger than the sum of its proper divisors (1).

227561821 is an equidigital number, since it uses as much as digits as its factorization.

227561821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 34.

The square root of 227561821 is about 15085.1523359892. The cubic root of 227561821 is about 610.5198658808.

The spelling of 227561821 in words is "two hundred twenty-seven million, five hundred sixty-one thousand, eight hundred twenty-one".