21321097 has 8 divisors (see below), whose sum is σ = 25649600. Its totient is φ = 17313264.

The previous prime is 21321089. The next prime is 21321101. The reversal of 21321097 is 79012312.

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 21321097 - 2³ = 21321089 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (21321067) 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 7 ways as a sum of consecutive naturals, for example, 80022 + ... + 80287.

It is an arithmetic number, because the mean of its divisors is an integer number (3206200).

Almost surely, 2^21321097 is an apocalyptic number.

It is an amenable number.

21321097 is a deficient number, since it is larger than the sum of its proper divisors (4328503).

21321097 is a wasteful number, since it uses less digits than its factorization.

21321097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160335.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 21321097 is about 4617.4773415795. The cubic root of 21321097 is about 277.2914733508.

The spelling of 21321097 in words is "twenty-one million, three hundred twenty-one thousand, ninety-seven".