20809455 has 16 divisors (see below), whose sum is σ = 33420384. Its totient is φ = 11056640.

The previous prime is 20809433. The next prime is 20809471. The reversal of 20809455 is 55490802.

It is not a de Polignac number, because 20809455 - 2⁵ = 20809423 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1747 + ... + 6683.

It is an arithmetic number, because the mean of its divisors is an integer number (2088774).

Almost surely, 2^20809455 is an apocalyptic number.

20809455 is a deficient number, since it is larger than the sum of its proper divisors (12610929).

20809455 is a wasteful number, since it uses less digits than its factorization.

20809455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5226.

The product of its (nonzero) digits is 14400, while the sum is 33.

The square root of 20809455 is about 4561.7381555718. The cubic root of 20809455 is about 275.0554378592.

The spelling of 20809455 in words is "twenty million, eight hundred nine thousand, four hundred fifty-five".