28910869 has 8 divisors (see below), whose sum is σ = 31220280. Its totient is φ = 26613696.

The previous prime is 28910851. The next prime is 28910881. The reversal of 28910869 is 96801982.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 288369 + 28622500 = 537^2 + 5350^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28910869 - 2⁷ = 28910741 is a prime.

It is a super-2 number, since 2×28910869² = 1671676692670322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28910899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2199 + ... + 7915.

It is an arithmetic number, because the mean of its divisors is an integer number (3902535).

Almost surely, 2^28910869 is an apocalyptic number.

It is an amenable number.

28910869 is a deficient number, since it is larger than the sum of its proper divisors (2309411).

28910869 is a wasteful number, since it uses less digits than its factorization.

28910869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6119.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 28910869 is about 5376.8828330177. The cubic root of 28910869 is about 306.9166024569.

The spelling of 28910869 in words is "twenty-eight million, nine hundred ten thousand, eight hundred sixty-nine".