20604553 has 4 divisors (see below), whose sum is σ = 21269248. Its totient is φ = 19939860.

The previous prime is 20604547. The next prime is 20604557. The reversal of 20604553 is 35540602.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20604553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20604557) 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, 332301 + ... + 332362.

It is an arithmetic number, because the mean of its divisors is an integer number (5317312).

Almost surely, 2^20604553 is an apocalyptic number.

It is an amenable number.

20604553 is a deficient number, since it is larger than the sum of its proper divisors (664695).

20604553 is an equidigital number, since it uses as much as digits as its factorization.

20604553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664694.

The product of its (nonzero) digits is 3600, while the sum is 25.

The square root of 20604553 is about 4539.2238323308. The cubic root of 20604553 is about 274.1496731408.

The spelling of 20604553 in words is "twenty million, six hundred four thousand, five hundred fifty-three".