20403321 has 16 divisors (see below), whose sum is σ = 29126400. Its totient is φ = 12665808.

The previous prime is 20403307. The next prime is 20403329. The reversal of 20403321 is 12330402.

It is not a de Polignac number, because 20403321 - 2¹¹ = 20401273 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20403321.

It is not an unprimeable number, because it can be changed into a prime (20403329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 330 + ... + 6396.

It is an arithmetic number, because the mean of its divisors is an integer number (1820400).

Almost surely, 2^20403321 is an apocalyptic number.

It is an amenable number.

20403321 is a deficient number, since it is larger than the sum of its proper divisors (8723079).

20403321 is a wasteful number, since it uses less digits than its factorization.

20403321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6148.

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 20403321 is about 4517.0035421726. The cubic root of 20403321 is about 273.2542680629.

Adding to 20403321 its reverse (12330402), we get a palindrome (32733723).

The spelling of 20403321 in words is "twenty million, four hundred three thousand, three hundred twenty-one".