21600397 has 36 divisors (see below), whose sum is σ = 29075040. Its totient is φ = 15668640.

The previous prime is 21600391. The next prime is 21600419. The reversal of 21600397 is 79300612.

It is not a de Polignac number, because 21600397 - 2⁷ = 21600269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21600391) 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 35 ways as a sum of consecutive naturals, for example, 696772 + ... + 696802.

It is an arithmetic number, because the mean of its divisors is an integer number (807640).

Almost surely, 2^21600397 is an apocalyptic number.

It is an amenable number.

21600397 is a deficient number, since it is larger than the sum of its proper divisors (7474643).

21600397 is a wasteful number, since it uses less digits than its factorization.

21600397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 21600397 is about 4647.6227256523. The cubic root of 21600397 is about 278.4970362200.

The spelling of 21600397 in words is "twenty-one million, six hundred thousand, three hundred ninety-seven".