28689013 has 8 divisors (see below), whose sum is σ = 30437208. Its totient is φ = 26947584.

The previous prime is 28688987. The next prime is 28689071. The reversal of 28689013 is 31098682.

It can be written as a sum of positive squares in 4 ways, for example, as 5098564 + 23590449 = 2258^2 + 4857^2 .

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

It is not a de Polignac number, because 28689013 - 2⁹ = 28688501 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28689113) 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, 9045 + ... + 11797.

It is an arithmetic number, because the mean of its divisors is an integer number (3804651).

Almost surely, 2^28689013 is an apocalyptic number.

It is an amenable number.

28689013 is a deficient number, since it is larger than the sum of its proper divisors (1748195).

28689013 is a wasteful number, since it uses less digits than its factorization.

28689013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3383.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 28689013 is about 5356.2125611294. The cubic root of 28689013 is about 306.1295142870.

It can be divided in two parts, 286890 and 13, that added together give a triangular number (286903 = T₇₅₇).

The spelling of 28689013 in words is "twenty-eight million, six hundred eighty-nine thousand, thirteen".