20490566 has 16 divisors (see below), whose sum is σ = 31933440. Its totient is φ = 9850440.

The previous prime is 20490557. The next prime is 20490599. The reversal of 20490566 is 66509402.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 9365 + ... + 11343.

It is an arithmetic number, because the mean of its divisors is an integer number (1995840).

Almost surely, 2^20490566 is an apocalyptic number.

20490566 is a deficient number, since it is larger than the sum of its proper divisors (11442874).

20490566 is a wasteful number, since it uses less digits than its factorization.

20490566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2179.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 20490566 is about 4526.6506381650. The cubic root of 20490566 is about 273.6431944360.

Adding to 20490566 its reverse (66509402), we get a palindrome (86999968).

The spelling of 20490566 in words is "twenty million, four hundred ninety thousand, five hundred sixty-six".