28997851 has 4 divisors (see below), whose sum is σ = 29489400. Its totient is φ = 28506304.

The previous prime is 28997833. The next prime is 28997861. The reversal of 28997851 is 15879982.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28997851 - 2⁷ = 28997723 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28997795 and 28997804.

It is not an unprimeable number, because it can be changed into a prime (28997861) 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, 245686 + ... + 245803.

It is an arithmetic number, because the mean of its divisors is an integer number (7372350).

Almost surely, 2^28997851 is an apocalyptic number.

28997851 is a deficient number, since it is larger than the sum of its proper divisors (491549).

28997851 is an equidigital number, since it uses as much as digits as its factorization.

28997851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491548.

The product of its digits is 362880, while the sum is 49.

The square root of 28997851 is about 5384.9652737970. The cubic root of 28997851 is about 307.2240934054.

The spelling of 28997851 in words is "twenty-eight million, nine hundred ninety-seven thousand, eight hundred fifty-one".