28736609 has 4 divisors (see below), whose sum is σ = 31349040. Its totient is φ = 26124180.

The previous prime is 28736581. The next prime is 28736623. The reversal of 28736609 is 90663782.

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 28736609 - 2⁸ = 28736353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28736629) 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, 1306199 + ... + 1306220.

It is an arithmetic number, because the mean of its divisors is an integer number (7837260).

Almost surely, 2^28736609 is an apocalyptic number.

It is an amenable number.

28736609 is a deficient number, since it is larger than the sum of its proper divisors (2612431).

28736609 is a wasteful number, since it uses less digits than its factorization.

28736609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2612430.

The product of its (nonzero) digits is 108864, while the sum is 41.

The square root of 28736609 is about 5360.6537847542. The cubic root of 28736609 is about 306.2987136726.

It can be divided in two parts, 28 and 736609, that added together give a palindrome (736637).

The spelling of 28736609 in words is "twenty-eight million, seven hundred thirty-six thousand, six hundred nine".