28456681 has 16 divisors (see below), whose sum is σ = 32669568. Its totient is φ = 24534400.

The previous prime is 28456651. The next prime is 28456717. The reversal of 28456681 is 18665482.

It is not a de Polignac number, because 28456681 - 2¹¹ = 28454633 is a prime.

It is a super-2 number, since 2×28456681² = 1619565387071522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28456651) 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, 34251 + ... + 35071.

It is an arithmetic number, because the mean of its divisors is an integer number (2041848).

Almost surely, 2^28456681 is an apocalyptic number.

It is an amenable number.

28456681 is a deficient number, since it is larger than the sum of its proper divisors (4212887).

28456681 is a wasteful number, since it uses less digits than its factorization.

28456681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992.

The product of its digits is 92160, while the sum is 40.

The square root of 28456681 is about 5334.4803870668. The cubic root of 28456681 is about 305.3008980703.

It can be divided in two parts, 284 and 56681, that added together give a palindrome (56965).

The spelling of 28456681 in words is "twenty-eight million, four hundred fifty-six thousand, six hundred eighty-one".