28993553 has 4 divisors (see below), whose sum is σ = 29360640. Its totient is φ = 28626468.

The previous prime is 28993541. The next prime is 28993571. The reversal of 28993553 is 35539982.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28993553 is a prime.

It is a super-2 number, since 2×28993553² = 1681252231127618, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28993583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 183425 + ... + 183582.

It is an arithmetic number, because the mean of its divisors is an integer number (7340160).

Almost surely, 2^28993553 is an apocalyptic number.

It is an amenable number.

28993553 is a deficient number, since it is larger than the sum of its proper divisors (367087).

28993553 is an equidigital number, since it uses as much as digits as its factorization.

28993553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367086.

The product of its digits is 291600, while the sum is 44.

The square root of 28993553 is about 5384.5661849401. The cubic root of 28993553 is about 307.2089139542.

The spelling of 28993553 in words is "twenty-eight million, nine hundred ninety-three thousand, five hundred fifty-three".