20321251 has 8 divisors (see below), whose sum is σ = 20950160. Its totient is φ = 19696608.

The previous prime is 20321243. The next prime is 20321261. The reversal of 20321251 is 15212302.

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 20321251 - 2³ = 20321243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20321201) 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 7 ways as a sum of consecutive naturals, for example, 10465 + ... + 12253.

It is an arithmetic number, because the mean of its divisors is an integer number (2618770).

Almost surely, 2^20321251 is an apocalyptic number.

20321251 is a deficient number, since it is larger than the sum of its proper divisors (628909).

20321251 is a wasteful number, since it uses less digits than its factorization.

20321251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2133.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 20321251 is about 4507.9098260724. The cubic root of 20321251 is about 272.8873978233.

Adding to 20321251 its reverse (15212302), we get a palindrome (35533553).

The spelling of 20321251 in words is "twenty million, three hundred twenty-one thousand, two hundred fifty-one".