28544781 has 8 divisors (see below), whose sum is σ = 38094624. Its totient is φ = 19012400.

The previous prime is 28544777. The next prime is 28544801. The reversal of 28544781 is 18744582.

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 28544781 - 2² = 28544777 is a prime.

It is a super-2 number, since 2×28544781² = 1629609044675922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28548781) 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, 106 + ... + 7556.

It is an arithmetic number, because the mean of its divisors is an integer number (4761828).

Almost surely, 2^28544781 is an apocalyptic number.

It is an amenable number.

28544781 is a deficient number, since it is larger than the sum of its proper divisors (9549843).

28544781 is a wasteful number, since it uses less digits than its factorization.

28544781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8731.

The product of its digits is 71680, while the sum is 39.

The square root of 28544781 is about 5342.7316047131. The cubic root of 28544781 is about 305.6156372774.

The spelling of 28544781 in words is "twenty-eight million, five hundred forty-four thousand, seven hundred eighty-one".