20029561 has 2 divisors, whose sum is σ = 20029562. Its totient is φ = 20029560.

The previous prime is 20029547. The next prime is 20029579. The reversal of 20029561 is 16592002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19971961 + 57600 = 4469^2 + 240^2 .

It is a cyclic number.

It is not a de Polignac number, because 20029561 - 2⁹ = 20029049 is a prime.

It is not a weakly prime, because it can be changed into another prime (20029501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10014780 + 10014781.

It is an arithmetic number, because the mean of its divisors is an integer number (10014781).

Almost surely, 2^20029561 is an apocalyptic number.

It is an amenable number.

20029561 is a deficient number, since it is larger than the sum of its proper divisors (1).

20029561 is an equidigital number, since it uses as much as digits as its factorization.

20029561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 20029561 is about 4475.4397549291. The cubic root of 20029561 is about 271.5754306566.

The spelling of 20029561 in words is "twenty million, twenty-nine thousand, five hundred sixty-one".