21288093 has 8 divisors (see below), whose sum is σ = 28531968. Its totient is φ = 14118144.

The previous prime is 21288083. The next prime is 21288119. The reversal of 21288093 is 39088212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21288093 - 2⁸ = 21287837 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21288013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17805 + ... + 18962.

It is an arithmetic number, because the mean of its divisors is an integer number (3566496).

Almost surely, 2^21288093 is an apocalyptic number.

It is an amenable number.

21288093 is a deficient number, since it is larger than the sum of its proper divisors (7243875).

21288093 is a wasteful number, since it uses less digits than its factorization.

21288093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36963.

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

The square root of 21288093 is about 4613.9021446060. The cubic root of 21288093 is about 277.1483216485.

The spelling of 21288093 in words is "twenty-one million, two hundred eighty-eight thousand, ninety-three".