28347681 has 8 divisors (see below), whose sum is σ = 37962880. Its totient is φ = 18815472.

The previous prime is 28347667. The next prime is 28347719. The reversal of 28347681 is 18674382.

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

It is not a de Polignac number, because 28347681 - 2¹¹ = 28345633 is a prime.

It is a super-2 number, since 2×28347681² = 1607182036155522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28347611) 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, 19945 + ... + 21318.

It is an arithmetic number, because the mean of its divisors is an integer number (4745360).

Almost surely, 2^28347681 is an apocalyptic number.

It is an amenable number.

28347681 is a deficient number, since it is larger than the sum of its proper divisors (9615199).

28347681 is a wasteful number, since it uses less digits than its factorization.

28347681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41495.

The product of its digits is 64512, while the sum is 39.

The square root of 28347681 is about 5324.2540322565. The cubic root of 28347681 is about 304.9105928031.

The spelling of 28347681 in words is "twenty-eight million, three hundred forty-seven thousand, six hundred eighty-one".