28666481 has 4 divisors (see below), whose sum is σ = 29207412. Its totient is φ = 28125552.

The previous prime is 28666433. The next prime is 28666489. The reversal of 28666481 is 18466682.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12666481 + 16000000 = 3559^2 + 4000^2 .

It is a cyclic number.

It is not a de Polignac number, because 28666481 - 2¹⁰ = 28665457 is a prime.

It is a super-2 number, since 2×28666481² = 1643534265846722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28666489) 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, 270386 + ... + 270491.

It is an arithmetic number, because the mean of its divisors is an integer number (7301853).

Almost surely, 2^28666481 is an apocalyptic number.

It is an amenable number.

28666481 is a deficient number, since it is larger than the sum of its proper divisors (540931).

28666481 is an equidigital number, since it uses as much as digits as its factorization.

28666481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540930.

The product of its digits is 110592, while the sum is 41.

The square root of 28666481 is about 5354.1087960556. The cubic root of 28666481 is about 306.0493498376.

The spelling of 28666481 in words is "twenty-eight million, six hundred sixty-six thousand, four hundred eighty-one".