28709253 has 12 divisors (see below), whose sum is σ = 41572908. Its totient is φ = 19091520.

The previous prime is 28709237. The next prime is 28709281. The reversal of 28709253 is 35290782.

It is a happy number.

28709253 is a nontrivial binomial coefficient, being equal to C(7578, 2).

It can be written as a sum of positive squares in 2 ways, for example, as 161604 + 28547649 = 402^2 + 5343^2 .

It is not a de Polignac number, because 28709253 - 2⁴ = 28709237 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28709053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1 + ... + 7577.

It is an arithmetic number, because the mean of its divisors is an integer number (3464409).

Almost surely, 2^28709253 is an apocalyptic number.

28709253 is the 7577-th triangular number and also the 3789-th hexagonal number.

It is an amenable number.

28709253 is a deficient number, since it is larger than the sum of its proper divisors (12863655).

28709253 is a wasteful number, since it uses less digits than its factorization.

28709253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8004 (or 8001 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 28709253 is about 5358.1016227765. The cubic root of 28709253 is about 306.2014884703.

The spelling of 28709253 in words is "twenty-eight million, seven hundred nine thousand, two hundred fifty-three".