20704321 has 4 divisors (see below), whose sum is σ = 22586544. Its totient is φ = 18822100.

The previous prime is 20704309. The next prime is 20704379. The reversal of 20704321 is 12340702.

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 not a de Polignac number, because 20704321 - 2¹⁷ = 20573249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20704721) 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, 941095 + ... + 941116.

It is an arithmetic number, because the mean of its divisors is an integer number (5646636).

Almost surely, 2^20704321 is an apocalyptic number.

It is an amenable number.

20704321 is a deficient number, since it is larger than the sum of its proper divisors (1882223).

20704321 is a wasteful number, since it uses less digits than its factorization.

20704321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1882222.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 20704321 is about 4550.2001054899. The cubic root of 20704321 is about 274.5914418044.

It can be divided in two parts, 20704 and 321, that added together give a square (21025 = 145²).

The spelling of 20704321 in words is "twenty million, seven hundred four thousand, three hundred twenty-one".