28621811 has 4 divisors (see below), whose sum is σ = 29608800. Its totient is φ = 27634824.

The previous prime is 28621807. The next prime is 28621819. The reversal of 28621811 is 11812682.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28621811 - 2² = 28621807 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 986959 = 28621811 / (2 + 8 + 6 + 2 + 1 + 8 + 1 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28621819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 493451 + ... + 493508.

It is an arithmetic number, because the mean of its divisors is an integer number (7402200).

Almost surely, 2^28621811 is an apocalyptic number.

28621811 is a deficient number, since it is larger than the sum of its proper divisors (986989).

28621811 is an equidigital number, since it uses as much as digits as its factorization.

28621811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 986988.

The product of its digits is 1536, while the sum is 29.

The square root of 28621811 is about 5349.9356070891. The cubic root of 28621811 is about 305.8902984383.

The spelling of 28621811 in words is "twenty-eight million, six hundred twenty-one thousand, eight hundred eleven".