20456321 has 8 divisors (see below), whose sum is σ = 21753864. Its totient is φ = 19169280.

The previous prime is 20456309. The next prime is 20456323. The reversal of 20456321 is 12365402.

It can be written as a sum of positive squares in 4 ways, for example, as 6431296 + 14025025 = 2536^2 + 3745^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20456321 - 2⁶ = 20456257 is a prime.

It is a super-2 number, since 2×20456321² = 836922137710082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20456323) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1601 + ... + 6593.

It is an arithmetic number, because the mean of its divisors is an integer number (2719233).

Almost surely, 2^20456321 is an apocalyptic number.

It is an amenable number.

20456321 is a deficient number, since it is larger than the sum of its proper divisors (1297543).

20456321 is a wasteful number, since it uses less digits than its factorization.

20456321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5251.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 20456321 is about 4522.8664583425. The cubic root of 20456321 is about 273.4906667403.

The spelling of 20456321 in words is "twenty million, four hundred fifty-six thousand, three hundred twenty-one".