28732009 has 8 divisors (see below), whose sum is σ = 31220480. Its totient is φ = 26341200.

The previous prime is 28732003. The next prime is 28732031. The reversal of 28732009 is 90023782.

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 28732009 - 2³ = 28732001 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28732001) 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, 23802 + ... + 24979.

It is an arithmetic number, because the mean of its divisors is an integer number (3902560).

Almost surely, 2^28732009 is an apocalyptic number.

It is an amenable number.

28732009 is a deficient number, since it is larger than the sum of its proper divisors (2488471).

28732009 is a wasteful number, since it uses less digits than its factorization.

28732009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48831.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 28732009 is about 5360.2247154387. The cubic root of 28732009 is about 306.2823692566.

The spelling of 28732009 in words is "twenty-eight million, seven hundred thirty-two thousand, nine".