28771681 has 8 divisors (see below), whose sum is σ = 31105280. Its totient is φ = 26520048.

The previous prime is 28771679. The next prime is 28771697. The reversal of 28771681 is 18617782.

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

It is not a de Polignac number, because 28771681 - 2¹ = 28771679 is a prime.

It is a super-2 number, since 2×28771681² = 1655619255131522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28771651) 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, 19761 + ... + 21166.

It is an arithmetic number, because the mean of its divisors is an integer number (3888160).

Almost surely, 2^28771681 is an apocalyptic number.

It is an amenable number.

28771681 is a deficient number, since it is larger than the sum of its proper divisors (2333599).

28771681 is a wasteful number, since it uses less digits than its factorization.

28771681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40983.

The product of its digits is 37632, while the sum is 40.

The square root of 28771681 is about 5363.9240300362. The cubic root of 28771681 is about 306.4232718760.

The spelling of 28771681 in words is "twenty-eight million, seven hundred seventy-one thousand, six hundred eighty-one".