28142321 has 2 divisors, whose sum is σ = 28142322. Its totient is φ = 28142320.

The previous prime is 28142299. The next prime is 28142329. The reversal of 28142321 is 12324182.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27667600 + 474721 = 5260^2 + 689^2 .

It is a cyclic number.

It is not a de Polignac number, because 28142321 - 2²² = 23948017 is a prime.

It is not a weakly prime, because it can be changed into another prime (28142329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14071160 + 14071161.

It is an arithmetic number, because the mean of its divisors is an integer number (14071161).

Almost surely, 2^28142321 is an apocalyptic number.

It is an amenable number.

28142321 is a deficient number, since it is larger than the sum of its proper divisors (1).

28142321 is an equidigital number, since it uses as much as digits as its factorization.

28142321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 768, while the sum is 23.

The square root of 28142321 is about 5304.9336470874. The cubic root of 28142321 is about 304.1725164906.

The spelling of 28142321 in words is "twenty-eight million, one hundred forty-two thousand, three hundred twenty-one".