28961909 has 8 divisors (see below), whose sum is σ = 30539040. Its totient is φ = 27390096.

The previous prime is 28961887. The next prime is 28961929. The reversal of 28961909 is 90916982.

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

It is not a de Polignac number, because 28961909 - 2²⁴ = 12184693 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28961909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28961929) 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, 15314 + ... + 17100.

It is an arithmetic number, because the mean of its divisors is an integer number (3817380).

Almost surely, 2^28961909 is an apocalyptic number.

It is an amenable number.

28961909 is a deficient number, since it is larger than the sum of its proper divisors (1577131).

28961909 is a wasteful number, since it uses less digits than its factorization.

28961909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2659.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 28961909 is about 5381.6269844723. The cubic root of 28961909 is about 307.0971091254.

The spelling of 28961909 in words is "twenty-eight million, nine hundred sixty-one thousand, nine hundred nine".