28123493 has 2 divisors, whose sum is σ = 28123494. Its totient is φ = 28123492.

The previous prime is 28123489. The next prime is 28123507. The reversal of 28123493 is 39432182.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23990404 + 4133089 = 4898^2 + 2033^2 .

It is a cyclic number.

It is not a de Polignac number, because 28123493 - 2² = 28123489 is a prime.

It is equal to p_1748624 and since 28123493 and 1748624 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28123483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14061746 + 14061747.

It is an arithmetic number, because the mean of its divisors is an integer number (14061747).

Almost surely, 2^28123493 is an apocalyptic number.

It is an amenable number.

28123493 is a deficient number, since it is larger than the sum of its proper divisors (1).

28123493 is an equidigital number, since it uses as much as digits as its factorization.

28123493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 32.

The square root of 28123493 is about 5303.1587756732. The cubic root of 28123493 is about 304.1046680500.

The spelling of 28123493 in words is "twenty-eight million, one hundred twenty-three thousand, four hundred ninety-three".