28685507 has 4 divisors (see below), whose sum is σ = 28804776. Its totient is φ = 28566240.

The previous prime is 28685479. The next prime is 28685521. The reversal of 28685507 is 70558682.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28685507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28685567) 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, 59273 + ... + 59754.

It is an arithmetic number, because the mean of its divisors is an integer number (7201194).

Almost surely, 2^28685507 is an apocalyptic number.

28685507 is a deficient number, since it is larger than the sum of its proper divisors (119269).

28685507 is a wasteful number, since it uses less digits than its factorization.

28685507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119268.

The product of its (nonzero) digits is 134400, while the sum is 41.

The square root of 28685507 is about 5355.8852676285. The cubic root of 28685507 is about 306.1170433828.

It can be divided in two parts, 28685 and 507, that added together give a palindrome (29192).

The spelling of 28685507 in words is "twenty-eight million, six hundred eighty-five thousand, five hundred seven".