28621311 has 4 divisors (see below), whose sum is σ = 38161752. Its totient is φ = 19080872.

The previous prime is 28621301. The next prime is 28621337. The reversal of 28621311 is 11312682.

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 28621311 - 2¹⁰ = 28620287 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28621301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4770216 + ... + 4770221.

It is an arithmetic number, because the mean of its divisors is an integer number (9540438).

Almost surely, 2^28621311 is an apocalyptic number.

28621311 is a deficient number, since it is larger than the sum of its proper divisors (9540441).

28621311 is an equidigital number, since it uses as much as digits as its factorization.

28621311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9540440.

The product of its digits is 576, while the sum is 24.

The square root of 28621311 is about 5349.8888773506. Note that the first 4 decimals coincide. The cubic root of 28621311 is about 305.8885172088. Note that the first 3 decimals are identical.

Adding to 28621311 its reverse (11312682), we get a palindrome (39933993).

The spelling of 28621311 in words is "twenty-eight million, six hundred twenty-one thousand, three hundred eleven".