20804453 has 4 divisors (see below), whose sum is σ = 20822688. Its totient is φ = 20786220.

The previous prime is 20804437. The next prime is 20804473. The reversal of 20804453 is 35440802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 35440802 = 2 ⋅17720401.

It is a cyclic number.

It is not a de Polignac number, because 20804453 - 2⁴ = 20804437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20804473) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7283 + ... + 9728.

It is an arithmetic number, because the mean of its divisors is an integer number (5205672).

Almost surely, 2^20804453 is an apocalyptic number.

It is an amenable number.

20804453 is a deficient number, since it is larger than the sum of its proper divisors (18235).

20804453 is a wasteful number, since it uses less digits than its factorization.

20804453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18234.

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 20804453 is about 4561.1898666905. The cubic root of 20804453 is about 275.0333975967.

The spelling of 20804453 in words is "twenty million, eight hundred four thousand, four hundred fifty-three".