20809313 has 16 divisors (see below), whose sum is σ = 25307520. Its totient is φ = 16713216.

The previous prime is 20809303. The next prime is 20809361. The reversal of 20809313 is 31390802.

It is a cyclic number.

It is not a de Polignac number, because 20809313 - 2⁶ = 20809249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20809303) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12095 + ... + 13707.

It is an arithmetic number, because the mean of its divisors is an integer number (1581720).

Almost surely, 2^20809313 is an apocalyptic number.

It is an amenable number.

20809313 is a deficient number, since it is larger than the sum of its proper divisors (4498207).

20809313 is a wasteful number, since it uses less digits than its factorization.

20809313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1736.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 20809313 is about 4561.7225913025. The cubic root of 20809313 is about 275.0548122148.

The spelling of 20809313 in words is "twenty million, eight hundred nine thousand, three hundred thirteen".