20288621 has 2 divisors, whose sum is σ = 20288622. Its totient is φ = 20288620.

The previous prime is 20288557. The next prime is 20288623. The reversal of 20288621 is 12688202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11222500 + 9066121 = 3350^2 + 3011^2 .

It is a cyclic number.

It is not a de Polignac number, because 20288621 - 2⁶ = 20288557 is a prime.

Together with 20288623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20288623) 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, 10144310 + 10144311.

It is an arithmetic number, because the mean of its divisors is an integer number (10144311).

Almost surely, 2^20288621 is an apocalyptic number.

It is an amenable number.

20288621 is a deficient number, since it is larger than the sum of its proper divisors (1).

20288621 is an equidigital number, since it uses as much as digits as its factorization.

20288621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 20288621 is about 4504.2891781057. The cubic root of 20288621 is about 272.7412603971.

The spelling of 20288621 in words is "twenty million, two hundred eighty-eight thousand, six hundred twenty-one".