21288097 has 8 divisors (see below), whose sum is σ = 22588416. Its totient is φ = 19993152.

The previous prime is 21288083. The next prime is 21288119. The reversal of 21288097 is 79088212.

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

It is a cyclic number.

It is not a de Polignac number, because 21288097 - 2¹⁵ = 21255329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21288067) 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, 9288 + ... + 11350.

It is an arithmetic number, because the mean of its divisors is an integer number (2823552).

Almost surely, 2^21288097 is an apocalyptic number.

It is an amenable number.

21288097 is a deficient number, since it is larger than the sum of its proper divisors (1300319).

21288097 is a wasteful number, since it uses less digits than its factorization.

21288097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2687.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 21288097 is about 4613.9025780786. The cubic root of 21288097 is about 277.1483390071.

The spelling of 21288097 in words is "twenty-one million, two hundred eighty-eight thousand, ninety-seven".