28792989 has 20 divisors (see below), whose sum is σ = 43172316. Its totient is φ = 19123776.

The previous prime is 28792957. The next prime is 28792991. The reversal of 28792989 is 98929782.

28792989 = 216² + 217² + ... + 458².

It can be written as a sum of positive squares in 2 ways, for example, as 13816089 + 14976900 = 3717^2 + 3870^2 .

It is not a de Polignac number, because 28792989 - 2⁵ = 28792957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28792189) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 29737 + ... + 30689.

Almost surely, 2^28792989 is an apocalyptic number.

It is an amenable number.

28792989 is a deficient number, since it is larger than the sum of its proper divisors (14379327).

28792989 is an equidigital number, since it uses as much as digits as its factorization.

28792989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1338 (or 1329 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The square root of 28792989 is about 5365.9098948827. The cubic root of 28792989 is about 306.4988978118.

The spelling of 28792989 in words is "twenty-eight million, seven hundred ninety-two thousand, nine hundred eighty-nine".