20256321 has 8 divisors (see below), whose sum is σ = 27125280. Its totient is φ = 13445792.

The previous prime is 20256319. The next prime is 20256323. The reversal of 20256321 is 12365202.

It is an interprime number because it is at equal distance from previous prime (20256319) and next prime (20256323).

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 20256321 - 2¹ = 20256319 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20256323) 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, 13791 + ... + 15188.

It is an arithmetic number, because the mean of its divisors is an integer number (3390660).

Almost surely, 2^20256321 is an apocalyptic number.

It is an amenable number.

20256321 is a deficient number, since it is larger than the sum of its proper divisors (6868959).

20256321 is a wasteful number, since it uses less digits than its factorization.

20256321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29215.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 20256321 is about 4500.7022785339. The cubic root of 20256321 is about 272.5964465158.

The spelling of 20256321 in words is "twenty million, two hundred fifty-six thousand, three hundred twenty-one".