28990007 has 4 divisors (see below), whose sum is σ = 29015736. Its totient is φ = 28964280.

The previous prime is 28990001. The next prime is 28990009. The reversal of 28990007 is 70009982.

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

It is a cyclic number.

It is not a de Polignac number, because 28990007 - 2¹⁸ = 28727863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28990001) 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, 11093 + ... + 13454.

It is an arithmetic number, because the mean of its divisors is an integer number (7253934).

Almost surely, 2^28990007 is an apocalyptic number.

28990007 is a deficient number, since it is larger than the sum of its proper divisors (25729).

28990007 is a wasteful number, since it uses less digits than its factorization.

28990007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25728.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 28990007 is about 5384.2369004345. The cubic root of 28990007 is about 307.1963892477.

Adding to 28990007 its reverse (70009982), we get a palindrome (98999989).

The spelling of 28990007 in words is "twenty-eight million, nine hundred ninety thousand, seven".