28216481 has 8 divisors (see below), whose sum is σ = 29994624. Its totient is φ = 26451520.

The previous prime is 28216477. The next prime is 28216493. The reversal of 28216481 is 18461282.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28216481 - 2² = 28216477 is a prime.

It is a super-2 number, since 2×28216481² = 1592339600046722, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28216411) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1316 + ... + 7626.

It is an arithmetic number, because the mean of its divisors is an integer number (3749328).

Almost surely, 2^28216481 is an apocalyptic number.

It is an amenable number.

28216481 is a deficient number, since it is larger than the sum of its proper divisors (1778143).

28216481 is a wasteful number, since it uses less digits than its factorization.

28216481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6591.

The product of its digits is 6144, while the sum is 32.

The square root of 28216481 is about 5311.9187682042. The cubic root of 28216481 is about 304.4394649594.

The spelling of 28216481 in words is "twenty-eight million, two hundred sixteen thousand, four hundred eighty-one".