20604521 has 4 divisors (see below), whose sum is σ = 23548032. Its totient is φ = 17661012.

The previous prime is 20604503. The next prime is 20604539. The reversal of 20604521 is 12540602.

It is a happy number.

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: 12540602 = 2 ⋅6270301.

It is an interprime number because it is at equal distance from previous prime (20604503) and next prime (20604539).

It is a cyclic number.

It is not a de Polignac number, because 20604521 - 2⁶ = 20604457 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20604493 and 20604502.

It is not an unprimeable number, because it can be changed into a prime (20604541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1471745 + ... + 1471758.

It is an arithmetic number, because the mean of its divisors is an integer number (5887008).

Almost surely, 2^20604521 is an apocalyptic number.

It is an amenable number.

20604521 is a deficient number, since it is larger than the sum of its proper divisors (2943511).

20604521 is an equidigital number, since it uses as much as digits as its factorization.

20604521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2943510.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 20604521 is about 4539.2203074978. The cubic root of 20604521 is about 274.1495312176.

The spelling of 20604521 in words is "twenty million, six hundred four thousand, five hundred twenty-one".