28078481 has 4 divisors (see below), whose sum is σ = 28763364. Its totient is φ = 27393600.

The previous prime is 28078471. The next prime is 28078487. The reversal of 28078481 is 18487082.

It is a happy number.

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 3168400 + 24910081 = 1780^2 + 4991^2 .

It is a cyclic number.

It is not a de Polignac number, because 28078481 - 2¹⁸ = 27816337 is a prime.

It is a super-2 number, since 2×28078481² = 1576802190534722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28078487) 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, 342380 + ... + 342461.

It is an arithmetic number, because the mean of its divisors is an integer number (7190841).

Almost surely, 2^28078481 is an apocalyptic number.

It is an amenable number.

28078481 is a deficient number, since it is larger than the sum of its proper divisors (684883).

28078481 is an equidigital number, since it uses as much as digits as its factorization.

28078481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684882.

The product of its (nonzero) digits is 28672, while the sum is 38.

The square root of 28078481 is about 5298.9131904571. The cubic root of 28078481 is about 303.9423403167.

The spelling of 28078481 in words is "twenty-eight million, seventy-eight thousand, four hundred eighty-one".