28641813 has 4 divisors (see below), whose sum is σ = 38189088. Its totient is φ = 19094540.

The previous prime is 28641793. The next prime is 28641853. The reversal of 28641813 is 31814682.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28641813 - 2¹⁸ = 28379669 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28641853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4773633 + ... + 4773638.

It is an arithmetic number, because the mean of its divisors is an integer number (9547272).

Almost surely, 2^28641813 is an apocalyptic number.

It is an amenable number.

28641813 is a deficient number, since it is larger than the sum of its proper divisors (9547275).

28641813 is an equidigital number, since it uses as much as digits as its factorization.

28641813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9547274.

The product of its digits is 9216, while the sum is 33.

The square root of 28641813 is about 5351.8046489012. The cubic root of 28641813 is about 305.9615377348.

The spelling of 28641813 in words is "twenty-eight million, six hundred forty-one thousand, eight hundred thirteen".