28989257 has 4 divisors (see below), whose sum is σ = 31624656. Its totient is φ = 26353860.

The previous prime is 28989227. The next prime is 28989293. The reversal of 28989257 is 75298982.

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 28989257 - 2¹⁰ = 28988233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28989217) 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, 1317683 + ... + 1317704.

It is an arithmetic number, because the mean of its divisors is an integer number (7906164).

Almost surely, 2^28989257 is an apocalyptic number.

It is an amenable number.

28989257 is a deficient number, since it is larger than the sum of its proper divisors (2635399).

28989257 is a wasteful number, since it uses less digits than its factorization.

28989257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2635398.

The product of its digits is 725760, while the sum is 50.

The square root of 28989257 is about 5384.1672522313. The cubic root of 28989257 is about 307.1937400673.

The spelling of 28989257 in words is "twenty-eight million, nine hundred eighty-nine thousand, two hundred fifty-seven".