20523321 has 32 divisors (see below), whose sum is σ = 37425920. Its totient is φ = 10824192.

The previous prime is 20523317. The next prime is 20523323. The reversal of 20523321 is 12332502.

20523321 is nontrivially palindromic in base 2.

It is not a de Polignac number, because 20523321 - 2² = 20523317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20523294 and 20523303.

It is not an unprimeable number, because it can be changed into a prime (20523323) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1720 + ... + 6633.

It is an arithmetic number, because the mean of its divisors is an integer number (1169560).

Almost surely, 2^20523321 is an apocalyptic number.

20523321 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20523321 is a deficient number, since it is larger than the sum of its proper divisors (16902599).

20523321 is a wasteful number, since it uses less digits than its factorization.

20523321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8382 (or 8376 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 20523321 is about 4530.2672106621. The cubic root of 20523321 is about 273.7889267219.

Adding to 20523321 its reverse (12332502), we get a palindrome (32855823).

The spelling of 20523321 in words is "twenty million, five hundred twenty-three thousand, three hundred twenty-one".