20505704 has 16 divisors (see below), whose sum is σ = 38500800. Its totient is φ = 10238832.

The previous prime is 20505691. The next prime is 20505707. The reversal of 20505704 is 40750502.

It is a self number, because there is not a number n which added to its sum of digits gives 20505704.

It is not an unprimeable number, because it can be changed into a prime (20505707) 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 in 3 ways as a sum of consecutive naturals, for example, 7079 + ... + 9545.

It is an arithmetic number, because the mean of its divisors is an integer number (2406300).

Almost surely, 2^20505704 is an apocalyptic number.

It is an amenable number.

20505704 is a deficient number, since it is larger than the sum of its proper divisors (17995096).

20505704 is a wasteful number, since it uses less digits than its factorization.

20505704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3512 (or 3508 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 23.

The square root of 20505704 is about 4528.3224266830. The cubic root of 20505704 is about 273.7105651305.

The spelling of 20505704 in words is "twenty million, five hundred five thousand, seven hundred four".