20227561 has 2 divisors, whose sum is σ = 20227562. Its totient is φ = 20227560.

The previous prime is 20227553. The next prime is 20227589. The reversal of 20227561 is 16572202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18870336 + 1357225 = 4344^2 + 1165^2 .

It is a cyclic number.

It is not a de Polignac number, because 20227561 - 2³ = 20227553 is a prime.

It is not a weakly prime, because it can be changed into another prime (20222561) 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, 10113780 + 10113781.

It is an arithmetic number, because the mean of its divisors is an integer number (10113781).

Almost surely, 2^20227561 is an apocalyptic number.

It is an amenable number.

20227561 is a deficient number, since it is larger than the sum of its proper divisors (1).

20227561 is an equidigital number, since it uses as much as digits as its factorization.

20227561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 20227561 is about 4497.5060867107. The cubic root of 20227561 is about 272.4673742608.

Adding to 20227561 its reverse (16572202), we get a palindrome (36799763).

The spelling of 20227561 in words is "twenty million, two hundred twenty-seven thousand, five hundred sixty-one".