28481813 has 2 divisors, whose sum is σ = 28481814. Its totient is φ = 28481812.

The previous prime is 28481807. The next prime is 28481821. The reversal of 28481813 is 31818482.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25180324 + 3301489 = 5018^2 + 1817^2 .

It is a cyclic number.

It is not a de Polignac number, because 28481813 - 2¹² = 28477717 is a prime.

It is a super-2 number, since 2×28481813² = 1622427343533938, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28481833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14240906 + 14240907.

It is an arithmetic number, because the mean of its divisors is an integer number (14240907).

Almost surely, 2^28481813 is an apocalyptic number.

It is an amenable number.

28481813 is a deficient number, since it is larger than the sum of its proper divisors (1).

28481813 is an equidigital number, since it uses as much as digits as its factorization.

28481813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12288, while the sum is 35.

The square root of 28481813 is about 5336.8354855663. The cubic root of 28481813 is about 305.3907488448.

The spelling of 28481813 in words is "twenty-eight million, four hundred eighty-one thousand, eight hundred thirteen".