28639645 has 16 divisors (see below), whose sum is σ = 36531648. Its totient is φ = 21479680.

The previous prime is 28639627. The next prime is 28639649. The reversal of 28639645 is 54693682.

It is not a de Polignac number, because 28639645 - 2¹⁷ = 28508573 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 (28639649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29010 + ... + 29980.

It is an arithmetic number, because the mean of its divisors is an integer number (2283228).

Almost surely, 2^28639645 is an apocalyptic number.

It is an amenable number.

28639645 is a deficient number, since it is larger than the sum of its proper divisors (7892003).

28639645 is a wasteful number, since it uses less digits than its factorization.

28639645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1340.

The product of its digits is 311040, while the sum is 43.

The square root of 28639645 is about 5351.6020965688. The cubic root of 28639645 is about 305.9538177702.

The spelling of 28639645 in words is "twenty-eight million, six hundred thirty-nine thousand, six hundred forty-five".