28709517 has 8 divisors (see below), whose sum is σ = 39001824. Its totient is φ = 18778448.

The previous prime is 28709453. The next prime is 28709519. The reversal of 28709517 is 71590782.

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 28709517 - 2⁶ = 28709453 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28709519) 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, 90123 + ... + 90440.

It is an arithmetic number, because the mean of its divisors is an integer number (4875228).

Almost surely, 2^28709517 is an apocalyptic number.

It is an amenable number.

28709517 is a deficient number, since it is larger than the sum of its proper divisors (10292307).

28709517 is a wasteful number, since it uses less digits than its factorization.

28709517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180619.

The product of its (nonzero) digits is 35280, while the sum is 39.

The square root of 28709517 is about 5358.1262583108. The cubic root of 28709517 is about 306.2024270405.

The spelling of 28709517 in words is "twenty-eight million, seven hundred nine thousand, five hundred seventeen".