28999999 has 4 divisors (see below), whose sum is σ = 33142864. Its totient is φ = 24857136.

The previous prime is 28999991. The next prime is 29000039. The reversal of 28999999 is 99999982.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99999982 = 2 ⋅49999991.

It is a cyclic number.

It is not a de Polignac number, because 28999999 - 2³ = 28999991 is a prime.

It is a Duffinian number.

28999999 is a modest number, since divided by 9999 gives 2899 as remainder.

It is a plaindrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 28999999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28999991) 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, 2071422 + ... + 2071435.

It is an arithmetic number, because the mean of its divisors is an integer number (8285716).

Almost surely, 2^28999999 is an apocalyptic number.

28999999 is a deficient number, since it is larger than the sum of its proper divisors (4142865).

28999999 is an equidigital number, since it uses as much as digits as its factorization.

28999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4142864.

The product of its digits is 8503056, while the sum is 64.

The square root of 28999999 is about 5385.1647142868. The cubic root of 28999999 is about 307.2316790372.

It can be divided in two parts, 28 and 999999, that multiplied together give a palindrome (27999972).

The spelling of 28999999 in words is "twenty-eight million, nine hundred ninety-nine thousand, nine hundred ninety-nine".