28709261 has 8 divisors (see below), whose sum is σ = 32881344. Its totient is φ = 24554880.

The previous prime is 28709237. The next prime is 28709281. The reversal of 28709261 is 16290782.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-28709261 is a prime.

It is a super-2 number, since 2×28709261² = 1648443334332242, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28709201) 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, 740 + ... + 7613.

It is an arithmetic number, because the mean of its divisors is an integer number (4110168).

Almost surely, 2^28709261 is an apocalyptic number.

It is an amenable number.

28709261 is a deficient number, since it is larger than the sum of its proper divisors (4172083).

28709261 is an equidigital number, since it uses as much as digits as its factorization.

28709261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8851.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 28709261 is about 5358.1023693095. The cubic root of 28709261 is about 306.2015169119.

The spelling of 28709261 in words is "twenty-eight million, seven hundred nine thousand, two hundred sixty-one".