28928013 has 12 divisors (see below), whose sum is σ = 40709088. Its totient is φ = 18269640.

The previous prime is 28927973. The next prime is 28928021. The reversal of 28928013 is 31082982.

It is not a de Polignac number, because 28928013 - 2⁸ = 28927757 is a prime.

It is a super-2 number, since 2×28928013² = 1673659872256338, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28928023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12273 + ... + 14438.

It is an arithmetic number, because the mean of its divisors is an integer number (3392424).

Almost surely, 2^28928013 is an apocalyptic number.

It is an amenable number.

28928013 is a deficient number, since it is larger than the sum of its proper divisors (11781075).

28928013 is a wasteful number, since it uses less digits than its factorization.

28928013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26752 (or 26733 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 28928013 is about 5378.4768289916. The cubic root of 28928013 is about 306.9772571367.

The spelling of 28928013 in words is "twenty-eight million, nine hundred twenty-eight thousand, thirteen".