28938997 has 4 divisors (see below), whose sum is σ = 28951020. Its totient is φ = 28926976.

The previous prime is 28938953. The next prime is 28939003. The reversal of 28938997 is 79983982.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 5503716 + 23435281 = 2346^2 + 4841^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28938997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28938937) 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, 1018 + ... + 7675.

It is an arithmetic number, because the mean of its divisors is an integer number (7237755).

Almost surely, 2^28938997 is an apocalyptic number.

It is an amenable number.

28938997 is a deficient number, since it is larger than the sum of its proper divisors (12023).

28938997 is an equidigital number, since it uses as much as digits as its factorization.

28938997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12022.

The product of its digits is 1959552, while the sum is 55.

The square root of 28938997 is about 5379.4978390181. The cubic root of 28938997 is about 307.0161054268.

The spelling of 28938997 in words is "twenty-eight million, nine hundred thirty-eight thousand, nine hundred ninety-seven".