28966981 has 4 divisors (see below), whose sum is σ = 29399392. Its totient is φ = 28534572.

The previous prime is 28966979. The next prime is 28967011. The reversal of 28966981 is 18966982.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18966982 = 2 ⋅9483491.

It is a cyclic number.

It is not a de Polignac number, because 28966981 - 2¹ = 28966979 is a prime.

It is a super-2 number, since 2×28966981² = 1678171976508722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28966921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 216105 + ... + 216238.

It is an arithmetic number, because the mean of its divisors is an integer number (7349848).

Almost surely, 2^28966981 is an apocalyptic number.

It is an amenable number.

28966981 is a deficient number, since it is larger than the sum of its proper divisors (432411).

28966981 is an equidigital number, since it uses as much as digits as its factorization.

28966981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432410.

The product of its digits is 373248, while the sum is 49.

The square root of 28966981 is about 5382.0981968002. The cubic root of 28966981 is about 307.1150350343.

Subtracting from 28966981 its reverse (18966982), we obtain a palindrome (9999999).

The spelling of 28966981 in words is "twenty-eight million, nine hundred sixty-six thousand, nine hundred eighty-one".