28420807 has 4 divisors (see below), whose sum is σ = 29081800. Its totient is φ = 27759816.

The previous prime is 28420771. The next prime is 28420811. The reversal of 28420807 is 70802482.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70802482 = 2 ⋅35401241.

It is a cyclic number.

It is not a de Polignac number, because 28420807 - 2¹⁵ = 28388039 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 (28420817) 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, 330432 + ... + 330517.

It is an arithmetic number, because the mean of its divisors is an integer number (7270450).

Almost surely, 2^28420807 is an apocalyptic number.

28420807 is a deficient number, since it is larger than the sum of its proper divisors (660993).

28420807 is an equidigital number, since it uses as much as digits as its factorization.

28420807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660992.

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 28420807 is about 5331.1168623470. The cubic root of 28420807 is about 305.1725512916.

The spelling of 28420807 in words is "twenty-eight million, four hundred twenty thousand, eight hundred seven".