20509708 has 6 divisors (see below), whose sum is σ = 35891996. Its totient is φ = 10254852.

The previous prime is 20509679. The next prime is 20509733. The reversal of 20509708 is 80790502.

It is a self number, because there is not a number n which added to its sum of digits gives 20509708.

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 as a sum of consecutive naturals, namely, 2563710 + ... + 2563717.

Almost surely, 2^20509708 is an apocalyptic number.

It is an amenable number.

20509708 is a deficient number, since it is larger than the sum of its proper divisors (15382288).

20509708 is a wasteful number, since it uses less digits than its factorization.

20509708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5127431 (or 5127429 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 20509708 is about 4528.7645114313. The cubic root of 20509708 is about 273.7283791296.

The spelling of 20509708 in words is "twenty million, five hundred nine thousand, seven hundred eight".