28993645 has 4 divisors (see below), whose sum is σ = 34792380. Its totient is φ = 23194912.

The previous prime is 28993637. The next prime is 28993693. The reversal of 28993645 is 54639982.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7584516 + 21409129 = 2754^2 + 4627^2 .

It is a cyclic number.

It is not a de Polignac number, because 28993645 - 2³ = 28993637 is a prime.

It is a super-3 number, since 3×28993645³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28993595 and 28993604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2899360 + ... + 2899369.

It is an arithmetic number, because the mean of its divisors is an integer number (8698095).

Almost surely, 2^28993645 is an apocalyptic number.

It is an amenable number.

28993645 is a deficient number, since it is larger than the sum of its proper divisors (5798735).

28993645 is an equidigital number, since it uses as much as digits as its factorization.

28993645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5798734.

The product of its digits is 466560, while the sum is 46.

The square root of 28993645 is about 5384.5747278685. The cubic root of 28993645 is about 307.2092388907.

The spelling of 28993645 in words is "twenty-eight million, nine hundred ninety-three thousand, six hundred forty-five".