28237381 has 2 divisors, whose sum is σ = 28237382. Its totient is φ = 28237380.

The previous prime is 28237337. The next prime is 28237403. The reversal of 28237381 is 18373282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20784481 + 7452900 = 4559^2 + 2730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28237381 is a prime.

It is a super-2 number, since 2×28237381² = 1594699371478322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28237301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14118690 + 14118691.

It is an arithmetic number, because the mean of its divisors is an integer number (14118691).

Almost surely, 2^28237381 is an apocalyptic number.

It is an amenable number.

28237381 is a deficient number, since it is larger than the sum of its proper divisors (1).

28237381 is an equidigital number, since it uses as much as digits as its factorization.

28237381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 34.

The square root of 28237381 is about 5313.8856781079. The cubic root of 28237381 is about 304.5146127012.

The spelling of 28237381 in words is "twenty-eight million, two hundred thirty-seven thousand, three hundred eighty-one".