28534781 has 16 divisors (see below), whose sum is σ = 32175360. Its totient is φ = 25082880.

The previous prime is 28534769. The next prime is 28534799. The reversal of 28534781 is 18743582.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28534781 is a prime.

It is a super-2 number, since 2×28534781² = 1628467453435922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28534081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49865 + ... + 50433.

It is an arithmetic number, because the mean of its divisors is an integer number (2010960).

Almost surely, 2^28534781 is an apocalyptic number.

It is an amenable number.

28534781 is a deficient number, since it is larger than the sum of its proper divisors (3640579).

28534781 is a wasteful number, since it uses less digits than its factorization.

28534781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724.

The product of its digits is 53760, while the sum is 38.

The square root of 28534781 is about 5341.7956718692. The cubic root of 28534781 is about 305.5799446660.

The spelling of 28534781 in words is "twenty-eight million, five hundred thirty-four thousand, seven hundred eighty-one".