28981081 has 4 divisors (see below), whose sum is σ = 30241152. Its totient is φ = 27721012.

The previous prime is 28981067. The next prime is 28981109. The reversal of 28981081 is 18018982.

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.

It is a cyclic number.

It is not a de Polignac number, because 28981081 - 2¹⁷ = 28850009 is a prime.

It is a super-2 number, since 2×28981081² = 1679806111857122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28981081.

It is not an unprimeable number, because it can be changed into a prime (28981021) 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, 630001 + ... + 630046.

It is an arithmetic number, because the mean of its divisors is an integer number (7560288).

Almost surely, 2^28981081 is an apocalyptic number.

It is an amenable number.

28981081 is a deficient number, since it is larger than the sum of its proper divisors (1260071).

28981081 is a wasteful number, since it uses less digits than its factorization.

28981081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1260070.

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 28981081 is about 5383.4079354996. The cubic root of 28981081 is about 307.1648575037.

The spelling of 28981081 in words is "twenty-eight million, nine hundred eighty-one thousand, eighty-one".