20321281 has 8 divisors (see below), whose sum is σ = 21054600. Its totient is φ = 19599360.

The previous prime is 20321269. The next prime is 20321293. The reversal of 20321281 is 18212302.

It is an interprime number because it is at equal distance from previous prime (20321269) and next prime (20321293).

It can be written as a sum of positive squares in 4 ways, for example, as 1040400 + 19280881 = 1020^2 + 4391^2 .

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 20321281 - 2⁷ = 20321153 is a prime.

It is a super-2 number, since 2×20321281² = 825908922961922, which contains 22 as substring.

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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 865 + ... + 6433.

It is an arithmetic number, because the mean of its divisors is an integer number (2631825).

Almost surely, 2^20321281 is an apocalyptic number.

It is an amenable number.

20321281 is a deficient number, since it is larger than the sum of its proper divisors (733319).

20321281 is an equidigital number, since it uses as much as digits as its factorization.

20321281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5699.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 20321281 is about 4507.9131535556. The cubic root of 20321281 is about 272.8875321100.

Adding to 20321281 its reverse (18212302), we get a palindrome (38533583).

It can be divided in two parts, 20321 and 281, that added together give a palindrome (20602).

The spelling of 20321281 in words is "twenty million, three hundred twenty-one thousand, two hundred eighty-one".